第一篇:建筑学毕业专业外文翻译文献
xx大学xx届本科毕业设计
专业文献翻译
本 科 毕 业 设 计(外文翻译)
题目 居住区交往空间规划与设计
院(系部)
xxx学院
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xx 年级班级
xx 学生姓名
xx 指导教师
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xx 年 xx 月 x 日
Planning and Design of Association Space of residential District xx大学xx届本科毕业设计
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Xia dong liang 【Abstract】:The association space refers to the indoor and outdoor space for communication between residents.The article presents an overall discussion of the necessity,hierarchy and functionality of association space,with a wish to create positive and healthy association atmosphere and stimulate good communication among residents so that the residential area can become a homeland full of love and harmony.
【Keyword】: residential area;association space;necessity;hierarchy; Functionality【Foreword】:As the housing system reform and the rapid development of real estate, urban residential areas large urban settlements have emerged on the layout of residential buildings, public buildings, public green space, life and living facilities such as roads, to provide urban residents live in the community and The establishment, is an integral part of the city.Exchanges between the living room area residents is to communicate and exchange of indoor and outdoor space.At this stage, people's living standards greatly improved the living environment of continuous improvement district.Developers should not only focus on residential construction and the reasonable comfort, paying greater attention to the construction of residential environment.However, the current environment in the construction of residential areas, they are often the natural ecology of greening the environment is much more to consider, and the promotion of exchanges between the residents of the space environment to consider less, environmental construction can not meet the occupants of the psychological characteristics and needs.From the basic physiological needs gradually to meet the psychological and cultural fields of promoting a higher level, the residential area is not only the function of living, but also people's thinking and feelings of the local exchange.Therefore, the strengthening of exchanges between the residential areas of space construction, increase residential neighbourhood affinity, should be developed in the planning and construction of residential areas should also consider the issue.How to conduct exchanges between the residential areas of space planning and design, improve people's quality of life, the author of his own real estate development 2 xx大学xx届本科毕业设计
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experience and try to contact the living room area of need, level of functionality for a Review.A residential area of exchanges between
The need for space Exchanges between the residential areas to create space for the process, in a sense, is in the course of exchanges between the people and the natural world and define the space environment between the development process.1.1 exchanges create a space to meet the spiritual and cultural needs of residents.Jan • Gaelic in the “contacts and space,” a book, the residents will live within the community of contacts divided into three categories: ① necessity of activities(such as school, work, etc.), the participants did not have much choice, subject to very little Material and environmental impact;②spontaneous activities(such as walking, wait-and-see stop, etc.), greatly dependent on the quality of material and the space environment:③social activities(such as children' games, chatting and people-to-people contacts between the passive January 1 simple See, hear, etc.), also, to a certain extent, the impact of material and the space environment.Therefore, the exchanges between the residential area of the space will create a direct impact on the residents of the contacts.As people's living standards gradually improved, the residents of the spiritual and cultural needs arising from the exchanges with the requirements will be getting higher and higher.1.2 Create a space of contacts is the need to maintain traditional family ties
Traditional historical neighborhoods and the living units Daza Yuan on the shape of an objective to maintain and develop the neighborhood family.As the market economy and the development of new residential development and construction, and many residents to move to multi-storey high-rise residential, the link between households and households reduce, and even people are not familiar with the portal.At the same one floor, did not know each other very common phenomenon, the traditional relations in the neighborhood gradually indifferent.Carry forward the traditional virtues, to promote family residential, Healthy demonstration projects in the country has long been proposed for residential “High-quality, new life”, which 3 xx大学xx届本科毕业设计
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“new life”, including guidance on the new concept of living, to guide the new consumer awareness, a new form of exchanges, to form a new management model, and so on five aspects.According to this standard, the exchanges create a space it is very important.1.3 Create a space of contacts is the need to build a harmonious society
Residential area is to build a harmonious society space unit, a harmonious society is an important part.A residential area of a harmonious society can be harmonious.Harmonious residential areas should be a moderate consumption of economic, social management, diversification and harmonious relations between the neighbors, living environment, and with the humanistic spirit and the rich local cultural characteristics of the geographical space.From the hardware side, there should be a scientific and rational planning, good construction quality, improve infrastructure, the complete establishment of contacts, good landscape.From the software side, there should be quality property management, and improve the community-based organizations, the rich cultural atmosphere, good morality.Therefore, the exchanges between the space as an integral part of residential areas, create a far-reaching significance, and China recently and residential real estate will be put on the “build a harmonious family residential district,” the objective is consistent.residential district-level exchanges between the space
The living space planning and construction in accordance with people at different times, different locations, different activities in different levels of privacy, can be divided into private space, semi-private room, semi-public space, public space, the formation of four space-related fields.The level and the field of space will help create a sense of belonging among the residents and enhance the interaction and pro-neighborhood and.People from the private space into the public space, is a gradual process.In this process, after all the residents of different levels of outdoor space, making contacts to become a necessity.2.1 residential building space to create exchanges
Dwellers in privacy is assured and meet under the premise of hope neighborhood close, harmonious and to mutual exchanges and contacts.Therefore, the need to have 4 xx大学xx届本科毕业设计
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exchanges between the space settings, and create a way as follows: 2.11 expand the staircase depth
Staircase is home residents in the buffer space, but also public housing tenants upstairs room at the break.The platform is too small to affect the length of stay of residents, not conducive to the exchanges between the residents.Expand the staircase depth, increase platform space, will increase their contacts, exchanges of opportunity.2.12 set up home gardens
Garden is home residents into the indoor space for the transition, here, achieved a semi-private room for the transition to private space, residents here can support grass flowers, reception guests.Nanjing-day Hong Villa-home platform into the home in the Garden set up a grill door, both outdoor green landscape will be conducted to the interior of the extension, for two people through the grille gate to create an opportunity for exchange.2.13 expand the unit foyer area
Unit in the entrance foyer area and configure the appropriate expansion of some facilities such as rest stool, reading Newspaper fence.a resident contacts, rest places, and units of the immediate household contacts.Conditional foyer can also do a lobby for households in this exchange, chat.2.14 bottom overhead
Residential Design for the elevated bottom of open space and ensure the smooth flow of green space on the ground.Supported by flowers, desk facilities as residents of rest, such as chat room, and in connection with outdoor landscape, easy to create a good atmosphere for exchanges.Even rainy day also will not be affected, adding unlimited life for fun.2.15 set-Gallery
Gallery of traditional Chinese architecture is a form of construction, is a form can be effective in promoting exchanges between the people of the fun of space incentives, are widely used in modern residential design, such as the Osmanthus flowers Hangzhou City District, Guangzhou Zhuyun Villa And so on.Gallery-factor here is traffic, and the exchange of places, played a role in the integration of the adjacent space, people can chat here, enjoy the sun, and so on.5 xx大学xx届本科毕业设计
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2.16 exchanges of high-rise building
The rising high-rise building in the physical environment restrictions on the freedom of the people exchanges, to reduce contact between the residents, the elderly rest, the lack of children' play space.Therefore, the high-rise building in the interval to set up a number of similar exchanges in the Chamber of good will to solve these problems.In this way, for the elderly in the rest of the space, to provide children with a playground, and the promotion of social interaction among residents.2.17 Roof Garden
On the platform set up in the roof garden, an increase of green space, was restored to the construction of the ground.People in this walk, fitness, chat, natural contact, an increase of exchanges between the residents of places to create a multi-level exchanges between the space.2.2 yards, a delegation of the association space
To achieve effective settlements between the groups and the exchanges have recognized the need for clear and appropriate areas of the border and logo.“ China's traditional courtyard space is part of building space, the area is a strong sense of space and border patterns, the neighborhood is to increase exchanges and contacts between the effective means.Beijing DaZayuan the old mode of living, residents of harmonious relations in harmony, a human face.Renowned architect Wu Liangyong design of the Beijing-juer infants alley, inheritance and development of this form of living.Gable wall residential use of the wrong column, platform height difference, changes in residential space, residential settings between Lianlang, plants of the tube, creating a ”siege without closure, without dredging through“ the group space and formed a semi-private, semi-public The field of space.In the courtyard between the layout desk, the elderly here have a rest and chat each other, no longer feel lonely;reserve some space, children play in the home, mothers can be seen here in the kitchen, children no longer worried about the safety of: Members of mutual Reference , And mutual exchanges, and exchanges are deep-seated.Not only enhance the feelings and prevent the formation of a collective consciousness, to effectively prevent the destruction and crime, security, have been protected.6 xx大学xx届本科毕业设计
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So that more people can enjoy the environmental landscape comfort, more and more developers are good attention to the landscape of the building.Pichu in the group in a space, as a delegation of the public landscape.However, they often re-design of ”visual effect“ light ”social effect.“ Although the construction of a large number of hardware shops, flower beds, shrubs planted Joe, it lacks some residents to promote exchanges between the rest of the shelters, chairs, and affected the exchanges between the extension of the neighborhood.Therefore, the delegation landscape in the strengthening of public infrastructure construction, and create a space for exchanges, will promote exchanges between the residents of outreach.2.3 exchanges between the public spaces to create space
By the semi-public space to public space, people exchanges between the exchanges from the neighborhood to the public exchanges, contacts between the characteristics of exchanges between the decision to create a space for the different practices.2.3.1 open space for public relations
Residential area of central green space is often the area of public venues, as shared by the entire population, is the residential area of the ”living room.“ Here, residents of various gatherings, community activities, fitness.Open space should be designed, without borders and at the same time, various groups in the residential area green space to the center of the road, should be easily accessible, guide the people into public space, to participate in contacts and exchanges.2.3.2 and landscape combine Pieces
Residential area of landscape and people's exchanges with the interaction between people in the landscape before the stop watch, the exchanges have the desire, with the landscape, more full of vigor.Therefore, public exchanges between the space and landscape Pieces should be combined, such as sculpture on the square, around the fountain Waterscape layout desk, people appreciate the side of sculpture, fountain, while exchanges and reduce the distance between people.At the same time should play a guiding role in the landscape, emphasizing participation, attractive to flow through the landscape, gathering popularity.exchanges between the living room area of the building features xx大学xx届本科毕业设计
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Different groups of people because of their age, occupation, cultural background of different exchanges of the functions of space have different needs.According to the characteristics of different populations and demand for space contacts between the different functions of the building, creating a different theme of space, will help attract people from outside, spontaneous interaction.3.1 exchanges between the functions of space and building occupants should be suited to the age structure
Children naturally active, have a strong sense of curiosity, games and more activities for climbing, jumping, leisure, and playing.Therefore, the venue should be set up in the slides, swings, Leisure Pool, bunkers and other facilities, taking into account the needs of adults to care for children, some blocks in the surrounding layout stool.On the one hand, children in the game was physical and mental exercise, on the other hand, care for the children of people have been exchanges.Young people like sports.Therefore, in order to increase the sports facilities, planning to basketball courts, tennis courts and other sports space.However, it should be far from some residential, so as to avoid interference on the daily life of residents.Like the elderly in the early morning fitness, such as doing Qigong, a tai chi, like the rest of the time playing chess, play cards, chat, feeding birds, such activities.Therefore, to make space in the small square, booths, equipped with platform, tables, chairs and other facilities.3.2 exchanges between the space to take into account the function of building barrier-free facilities layout
Exchanges between the living room area is a complex environment, including roads, green space, Pieces, facilities and other environmental factors.Exchanges between the functions of building space in addition to meet the normal use, should give full consideration to the disabled, the elderly vulnerable groups, such as the use of a barrier-free design.Barrier-free environment of space means exchanges with no obstruction and dangerous.If the import unit designed around 1.5 m x 1.5m above the level of space for wheelchair users stay;unit foyer reserved space for wheelchairs and Childs vehicles to facilitate wheelchair and Childs vehicles stored: in public relations to the road space On both sides, who set up blind road trip on the trail for the blind 8 xx大学xx届本科毕业设计
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walking: the sidewalk in the end, a height difference of the junction, a height difference of public platform set up the ramp for wheelchair users access;elderly morning exercises in the square, as far as possible Be flat no height difference, the use of anti-skid surfacing materials: children playing in the park, the use of soft mats and safety warning signs in different exchanges of space, by setting up the Pieces and personalized theme sculpture, to enhance space And the recognition of sexual orientation, and so on.Conclusion
In residential areas of planning and construction, we must be people-centered, according to create a functional level and living space area contacts at all levels, from the psychological and physical needs of starting, through the space environment to create, create a positive, healthy exchanges between the atmosphere, Residential area into a harmonious family homes.Meanwhile, the exchanges between the living room area of thinking and innovation, and developers need to continue to carry out exploration.References
[1] Yang • Gaelic.Exchanges and space [M].Beijing: China Building Industry Press.[2] Wang.Living in the community, ”the neighborhood exchanges“ and ”space" of [J], building knowledge, 2004(3):13-1 5.[3] Nie Lan Sheng Health, Song Kun.Create a pleasant living space-LJ.Architectural Journal, 1997(11):29-31 xx大学xx届本科毕业设计
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居住区交往空间规划与设计
夏良东
【摘要】 居住区交往空间是居民进行沟通与交流的户内、户外空间:文章从交往空间营造的必要性、层次性、功能性加以综述,旨在通过交往空间的营造,创造出积极、健康的交往氛围,促进居民交往,使居住区成为亲情和谐的家园。【关键词】 居住区;交往空间;必要性;层次性;功能性
前言:随着住房制度的改革和房地产业的迅猛发展,城市居住区大量涌现城市居住区集中布置了居住建筑、公共建筑、公共绿地、生活性道路等居住设施,为城市居民提供生活居住和从事社会活动的场所,是城市的有机组成部分。居住区交往空间是居民进行沟通与交流的户内、户外空间。
现阶段,人们的生活水平大大提高,居住区环境得到不断改善。开发者不仅要注重住宅建筑的合理与舒适,更要注重居住区环境的建设。然而,目前在居住区环境建设中,他们往往对自然生态的绿化环境考虑得多,而对促进居民交往的空间环境考虑得少,环境建设不能满足居住者的心理特征和需求。从基本生理需求的满足逐步向心理与文化领域的更高层次推进,居住区不单是居住的功能,同时也是人们思想与情感交流的地方。因此,加强居住区交往空间建设,增进居住区的邻里亲和力,应是开发者在居住区规划建设应同时考虑的问题。
如何进行居住区交往空间的规划与设计,提高人们的生活质量,笔者结合自己的房产开发经验,试对居住区交往空间的必要性、层次性、功能性作一综述。居住区交往空间的必要性
居住区交往空间营造的过程,从某种意义上讲,就是在人与人交往过程中进行人与自然空间环境关系界定并发展的过程。1.1 交往空间的营造是满足居住者精神文化的需要。
在扬·盖尔的《交往与空间》一书中,将居住社区内居民的交往活动分为三类 :①必要性活动(如上学、上班等),参与者没有多少选择的余地,很少受物质环境影响;②自发性活动(如散步、驻足观望等),大大地依赖于物质空间环境的质量;③社会性活动(如儿童游戏、聊天以及人与人之间的被动式接触——简单地看、听等),也在一定程度上受物质空间环境的影响。因此,居住区交往空间的营造将直接影响到居住者的交往活动。随着人们物质生活水平的逐渐提高,居住者对精神文化的需求引起对交往活动的要求将越来越高。
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1.2 交往空间的营造是维系传统亲情的需要
传统历史街区和单位大杂院的居住形态在客观上维系并发展了邻里亲情。随着市场经济的发展和新的住宅区的开发建设,许多居民搬到多层和高层住宅中,住户与住户之间联系减少,甚至于对门人家都不熟识。在同一幢楼中,彼此间不曾相识的现象很普遍,传统的邻里关系在逐渐淡漠。发扬传统美德,推广亲情住宅,国家康居示范工程中早已对住宅提出了。
“高品质、新生活”的要求,其中“新生活”就包括引导新的居住理念,引导新的消费意识,形成新的交往形态,形成新的管理模式等五个方面内容。按照这个标准,交往空间的营造就显得非常重要。1.3 交往空间的营造是构建和谐社会的需要
居住区是构建和谐社会的空间单元,是和谐社会的重要组成部分。居住区和谐了,社会才能和谐。和谐的居住区应是一个经济消费适度化、社会管理多元化、邻里关系和谐化、居住环境生态化,并具有浓郁的人文精神和地方文化特色的地域空间。从硬件方面看,应该有科学合理的规划、良好的建筑品质、完善的基础设施、完备的交往场所、较好的景观园林。从软件方面看,应该有优质的物业管理、健全的社区组织、浓郁的文化氛围、良好的道德风尚。因此,交往空间作为居住区的组成部分,其营造的意义是深远的,与近来中国房地产及住宅研究会提出的 “打造亲情和谐住宅小 区”的目标是相一致的。居住区交往空间的层次性
居住空间的规划与建设根据人们在不同时间、不同地点、不同活动中不同程度的私密性,可划分为私密空间、半私密空间、半公共空间、公共空间,形成四级空间领域。这样的空间层次和领域划分将有助于形成居住者的归属感,增进邻里的互动和亲和。人由私密空间进入到公共空间,是一个渐进的过程,在这个过程中,居住者经过了各个不同层次的室外空间,使得交往成为一种必然。2.1 住宅建筑交往空间的营造
居住者在私密性得到保证和满足的前提下,希望邻里关系密切、融洽,能够相互交流和交往。因此,需要有交往空间的设置,营造手法有以下几种: 2.1.1 扩大楼梯平台深度
楼梯平台是居民入户处的缓冲空间,同时又是楼上住户上楼时的休息空间。过小的平台将影响居民的停留时间,不利于居民之间的交往。扩大楼梯平台深度,增大平台面积,将增加他们联络、交往的机会。
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2.1.2 设置入户花园
入户花园是居民进入室内的过渡空间,在这里实现了半私密空间向私密空间过渡,居民可以在这里种花养草,接待来客。南京天泓山庄在入户平台进入入户花园处设置了格栅门,既将室外绿化景观向室内进行了延伸,又为两户人家透过格栅门进行交流创造了机会。2.1.3 扩大单元门厅面积
在单元入口门厅适当扩大面积并配置一些设施,如休息凳、阅报栏等,形成居民交往、休息的场所,实现单元住户的即时交往。有条件的门厅还可以做一个大堂,供住户在此交流、聊天。2.1.4 底层架空
住宅底层架空设计为开放式空间,保证了地面绿地的畅通。配以花草、坐凳等设施,作为居民休息、聊天等空间,再联系室外景观,易于创造出良好的交往氛围。即使下雨天也不受影响,为生活增添了无限乐趣。2.1.5 设置通廊
通廊是中国传统建筑的一种建筑形式,是一种能有效地促进形成人们交往乐趣的空间诱因,目前被广泛地运用在现代住宅的设计中,如杭州的桂花城小区、广州的竹韵山庄等。通廊在这里既是交通要素,又是交流场所,起到了相邻空间融合的作用,人们可以在此攀谈、晒太阳等。2.1.6 高层建筑交往层
高层住宅的不断攀升,在物质环境上限制了人们交往的自由,使居民之间接触减少,老人休息、儿童游戏的空间缺少。因此,在高层建筑中间隔数层设置一个类似中庭的交往层将较好地解决这些问题。这样,为老人提供了休息的空间,为儿童提供了游戏场所,又促进了居民之间的社会交往。2.1.7 屋顶花园
在屋顶平台上设置花园,增加了绿化空间,又恢复了被建筑占去的地面。人们在此散步、健 身、聊天,接触自然,增加了居民的交往场所,创造出多层次的交往空间。
2.2 庭院、组团交往空间的营造
“要实现住区群体间有效的交往并产生认同,必须有明确和恰当的领域范围和边界标识”。院落空间是我国传统建筑空间的一部分,是具有较强领域感和边界的空间形态,是增加邻里交流、交往的有效手段。北京旧时大杂院的居住模式,12 xx大学xx届本科毕业设计
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居民关系和睦融洽、富有人情味。著名建筑大师吴良镛设计的北京菊儿胡同,继承并发展了这一居住形态。
利用住宅的山墙错列、地台高差、变化住宅间距,住宅间设置连廊、植物的围合,营造出“围而不闭、透而不疏”的组团空间,形成了半私密、半公共的空间领域。在庭院间布置坐凳,老人在这里歇脚,促膝谈心,不再感到孤寂;预留一些空地,小孩在院中嬉戏,母亲在厨房可以看到这里,小孩的安全性不再担心;大家相互照应,相互交流,交往是深层次的。既增进了感情,又形成了集体的防范意识,有效地防止了破坏和犯罪,安全得到了保护。
让更多的人能享受到景观环境带来的舒适感,越来越多的开发商重视景观的均好性建设。在组团中辟出一块空间,作为组团的公共景观。然而,在设计中他们往往重“景观效应”,轻“社会效应”。虽建有大量的硬质铺地、花坛,种植乔灌木,却缺乏一些促进居民交往、休息的凉亭、坐椅,影响了邻里交往的外延。因此,在组团景观中加强公共设施建设,营造交往空间,将促进居民交往行为的向外拓展。
2.3 公共场地交往空间的营造
由半公共空间到公共空间,人们的交往由邻里交往转向公共交往,交往的特点决定了交往空间营造手法的不同。2.3.1 开放的公共交往空间
居住区的中心绿地往往是小区的公共场地,为全体居民所共享,是居住区的 “客厅”。在这里,居民进行各种聚会、社区活动、健身。空间设计应该是开敞的、无边界的,同时,在居住区各个组团空间通往中心绿地的道路,应便捷通达,引导人们融入到公共空间,参与交往和交流。2.3.2 与景观小品相结合
居住区的景观与人的交往有相互作用的关系,人们在景观前驻足观赏,产生交流的欲望,景观有了人的活动,更加富有生机。因此,公共交往空间应与景观小品相结合,如在广场雕塑、喷泉水景 四周布置坐凳,人们一边欣赏雕塑、喷泉,一边进行交流,拉近了人与人之间的距离。同时应发挥景观的引导作用,强调参与性,通过景观来吸引人流聚集人气。居住区交往空间的功能建设
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不同人群由于年龄、职业、文化背景的不同,对交往空间的功能有不同的需求。根据不同人群的特点和需求,进行交往空间的不同功能建设,营造出不同的主题空间,将有利于吸引人们走出户外,自发的进行交往。
3.1 交往空间的功能建设应与居住者的年龄结构相适应
儿童天性好动有强烈的好奇心,游戏活动多为攀爬、跳跃、嬉水、戏耍等。因此,在场地中应设置滑梯、秋千、戏水池、沙坑等设施,同时考虑大人照看小孩的需要,在周围布置一些座凳。一方面,孩子在游戏 中身心得到了锻炼,另一方面,照看小孩的大人们也得到了交流。
青年人喜欢体育运动。因此,要增加体育设施,规划出篮球场、网球场等运动空间。但应当离住宅远一些,以免造成对居民 日常生活的干扰。老年人喜欢在清晨健身,如做气功、打太极拳等,在其余的时间喜欢下棋、打牌、聊天、养鸟等活动。因此,在空间中宜做成小型广场、亭,配备台、桌、椅等设施。
3.2 交往空间的功能建设要兼顾无障碍设施布置
居住区交往空间是一个环境综合体,包括道路、绿地、小品、设施等多种环境因素。交往空间的功能建设除满足正常人的使用外,应充分考虑残疾人、老年人等弱势群体的使用,进行无障碍设计。无障碍系指交往空间环境中无障碍物和危险性。如在单元入口周围设计 1.5m x 1.5m以上的水平空间,便于轮椅使用者停留;单元门厅预留轮椅和童车的空间,方便轮椅和童车存放;在通往公共交往空间的道路两侧,人行步道上设置盲道,方便盲人行走;在人行道的端部、有高差的路口、有高差的公共平台设置坡道,供轮椅使用者通行;在老人晨练的广场,尽可能做到平坦无高差,采用防滑的铺装材料;在儿童嬉戏的乐园,采用柔软 的地垫和安全警示标志;在不同的交往空间,通过设置个性化的小品和主题雕塑,来增强空间的导向性和识别性等。结语
在居住区的规划建设中,要以人为本,按层次和功能营造居住区各级交往空间,从人的心理和生理需求出发,通过空间环境的营造,创造出积极、健康的交往氛围,使居住区成为亲情和谐的家园。同时,对居住区交往空间的思考和创新,需要开发者不断地进行探索。
参考文献
[1] 扬·盖尔;交往与空间[M].北京:中国建筑工业出版社.
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[2] 王华;居住社区中的“邻里交往”与“空间环境”分析[J],建筑知识,2004(3):13—15.
[3] 聂兰生,宋昆;营造宜人的居住空间[J].建筑学报,1997(11):29-31.
第二篇:建筑学外文翻译
武汉科技大学本科毕业设计外文翻译
LOUISIANA MANIFESTO
Jean Nouvel World Architecture.May2010 Vol.05.21~23
路易斯安那宣言
让·努维尔
世界建筑.2010年5月第05期.21~23页
武汉科技大学本科毕业设计外文翻译
摘要:让·努维尔的“路易斯安那宣言”是他对于当今建筑的思考和想法最为深刻的表达。这篇文章和他的项目与短片,在2005年6月7日-9月18日,于丹麦的路易斯安那现代艺术博物馆展出。它曾以多种文字出版。其哲学的基本原则是,一个建筑是有生命的、唯一的、特殊的,并且要与其周围环境、场所精神和谐共处。该展览是让·努维尔工作室、特约馆长让-路易斯·弗洛门特和路易斯安那博物馆合作举办的。(维雷娜·辛德勒)
关键词:路易斯安那;建筑设计;现代艺术博物馆;意识形态;场所精神
2005年,建筑更加倍地在消除地方的特征,把它们变得平庸无奇,蛮横地对待它们。它有时会取代风景,独自创造风景,这不过是另一种抹去风景的方式。但是,相反,路易斯安那是情感的震撼。体现出一个很快被遗忘的真理:建筑具有超越的能力。建筑能够显露地理、历史、色彩、植被、视野、光线。它以桀敖不驯、自然不做作的姿态来到这世界、并活着。它独一无二。它体现了路易斯安那精神。
它是一个小世界,一个气泡。没有任何形象、没有任何言论能够彰显它的深度。你必须身临其境才能体验到这一切,才会相信。建筑是我们世界的延伸,当世界不断在缩小时。当我们用愈来愈快的速度在全球到处跑;当我们聆听和观看相同的全球网络,分享相同的灾难所引起的震动;当我们随着相同的畅销歌曲的节奏跳舞,看着相同的球赛;当全球充斥着相同的影片,明星是全球人物;当一国总统想要统治世界;当我们到克隆商场购物,在同样的幕墙后头上班„„以及,当世界变小理当产生的好处不被列为全球重点课题时„„好比说,为什么教育无法通过相同的全球网络,更快速、确实地消除文盲?为什么能够拯救世界性流行病患者的药品无法及时送达?在这个追求高效率和盈利、配有一整套经济概念的意识形态特征愈来愈明显的世界,面对这些新情况,建筑同样难以幸免。
今天,全球化的影响不断深化,主流建筑旗帜鲜明地主张要“去脉络化”。然而,没有人去讨论这个急剧发展的形势所具有的意义:建筑评论,以建筑学科的界限为由,满足于美学和风格上的笼统论述,缺乏对现实的分析,并且忽略了重要的历史课题,亦即全球性建筑和“因地制宜”的建筑、普通性建筑和特殊性建筑之间日益强烈的对峙和冲突。今天的现代性难道只是直接继承20世纪的现代性、而不带任何批判精神?它难道只是在世界各地散播大量孤立存在的事物?它难道不应该去寻找理由、对应、相同、差异,以提出针对此时此地的特殊性建筑?路易斯安那作为具象征意义的角斗场,被选来进行这场犹如大卫对抗巨人歌利亚、“因地制宜”建筑的拥护者对抗“去脉络化”建筑的受益者的新战斗。毫无疑问,这场对抗比全球与地方之间的对抗更为深沉、复杂。特殊性与知识的更新有关。建筑知识本质上就是多元多样、与所有文明发生联系的;旅行是建造者的文化素养上一个重要的组成部分。我们熟知希腊、罗马或埃及旅行对建筑师多么重要。路易斯安那则是加州之旅的结晶:在这里,同样是透过对照和汇整距离遥远的不同讯息,构思出能够诠释一个独特情况的建筑方案。
当然,普遍性建筑在20世纪简单化的现代主义意识形态所遗留下来的功能主义这块粪肥上蓬勃发展。《雅典宪章》当初也提倡人文主义精神,然而,狂热人士、犬儒者和腐败者进行大量教条式地歪曲模仿,留给了我们一个灾难性的都市遗产。以生活在这个世界的快乐之名,我们必须抗拒建立在区块、网络、格网基础上的城市主义。这样自动的腐化堕落,让世界各地、不论何种气候形态的城市失去了身份。它以克隆办公大楼、2 武汉科技大学本科毕业设计外文翻译
克隆住家、克隆商场为食。它渴求别人事先想好的想法、别人事先创造的景观,以避免自己去思考和观察。
对于这些普遍性和建筑上的领土整治规则,我们必须用建立在对有生命经验的景观所做的结构性分析的基础上所产生的其他规则来取代它们。没错,建筑!因为建筑存在于各个层次,而城市主义则不存在;那不过是卑屈顺服的建筑在宏观层次上所做的拙劣变装演出,它的发展是为了替大量普遍性建筑的到来铺路。我们必须建立敏感的、诗意的规则:谈论色彩、本质、个性、无拘无束地创造,结合雨、风、海、山相关的特殊性的建筑方向。会谈论时空的连续,会为传承下来的混乱指引转变、修改的方向,会关注我们城市的分形结构中每一个层级的规则。这些敏感的规则不得不去挑战普遍的意识形态;普遍的意识形态有不断扩散霸权主流技术、以产生依赖的趋势,它倾向将所有的交通、能源和卫生体系变得愈来愈巨大,制造出一个庞然大物。
相反地,特殊的意识形态渴望自主,渴望使用当地和不同时候所提供的资源,渴望对非物质的侧重。我们该如何使用当地、而不是别处的资源?我们该如何创造具差异性的建筑,而不落入对刻板印象的夸张模仿?我们该如何进行深化?建筑设计并非从无到有的创造。建筑意味着在现有和已存在的基础上加以改造、转化。建筑意味着激励深藏于场所自身的特质,而由此具有自我创造的倾向。它意味着揭示、指引方向。它意味着延续活的历史以及它过往的轨迹。它意味着倾听一个有生命的地方的呼吸和脉动。它意味着诠释这些律动用于创造。建筑必须被视为对一个物质、原子、生物连续体的改造。它是在宏观与纳米物理学愈来愈令人头晕目眩之际,对我们这个广大世界里的某个片断的改造。不论转变、场所、建筑的规模是大是小,我们该如何表达一个有生命的断片发生转变时的难以预料?我们是否能够藉由符号、映像、种植来掌握可见的构成部分——云、植物、各种大大小小的生命机体?我们该如何创造出能够召唤隐藏的深度、灵魂的振动?这必然是一项诗意的任务,因为唯有诗懂得如何产生“瞬间的形而上学”:关于所能掌握的极限,关于奥秘、脆弱、自然;关于时间的作用、因年久而生成的色泽、会发生变化;关于不完美,因为不完美显露了我们可以达到的极限。那些扼杀情感的建筑不是具路易斯安那精神的建筑。而是在全球游走的艺术家兼建筑师、那些重复大师的作品,他们对完美、干枯、恒久不变的细节的追求,是情感无能的真实告白!重复制作“精通熟练的”细节,体现了他们对世界上建筑该有的本质感觉迟钝。大规模建造被误解!繁重和夸大是建筑上装腔作势的途径!细节就跟整体一样,是发明、移动、丰富世界的机会,是重新构成、重新组合、诱发各种质地、光线、不大可能的技术相遇的机会。然而,普遍性细节和普遍性建筑一样,属于预先制作、不存怀疑、没有危险、离可行的和可感觉的极限有一大段距离的领域;它以到处存在、到处可贩卖、传播一致性、扼杀差异、大量繁殖为使命。我们处在一种简单化思维的领地——系统的、使人放心的领地。我们距离产生吸引力的绝对条件——亦即自然不造作——非常遥远。能够在二元性、在对话当中创造独特性的建筑,能够面对一种情况来创造独特性的建筑,就是具路易斯安那精神的建筑。
这和那些不断重复某种形式、风格——它被视为“艺术家的签名”——的艺术家兼建筑师的态度完全相反。它和可以在任何时候空降到任何地方的建筑完全相反。这个全球现象是强调不属于任何场所、可以被移动位置、专为直接进入美术馆严密精确的白色格子而设计的20世纪艺术的延续。独立存在的建筑和可以孤立存在的艺术作品相反,3 武汉科技大学本科毕业设计外文翻译
它注定要发生干扰,它的出现犹如荒唐可笑的拼贴、突如其来的喷嚏——不过可惜的是,建筑领域经常缺乏超现实主义的敏感度„„
建筑意味着某些人凭着他们的意志力、渴望和知识,在某个时代对某个地方进行改造。我们从来就不是在单独地建筑。我们总是在某处建筑——当然是为某个人或某些人,但也总是为所有人。我们必须停止将建筑局限在采借一种风格上。我们的时代需要不断怀疑、寻找、不认为自己已经找到答案的建筑师,需要不畏风险、重新发现实证主义价值观、在建造的同时发明建筑、会让自己讶异、会在自己窗户上发现霉菌并知道如何解读的建筑师。让我们将替虚荣的城市化妆的工作,留给那些自认为美容师的建筑师。从今而后,建筑将在不可言喻、含糊模棱和不完美中重新发现它的光环!只有当建筑师摔了跤并改变时,他才知道自己已经尽了最大的努力:从创造到改造;从断言到暗示;从建造到嵌入;从建构到渗透;从放置到迭置;从清晰到含糊;从增加到偏移;从书法到抓痕、涂抹„„
相对于“控制、留下永恒的记号”这些陈旧过时的建筑目标,我们今天要以寻找在某地生活的乐趣为目标。让我们记住,建筑同时也是一种压迫、制约行为的工具。我们永远别让任何人来查禁这个享乐主义式的追求,尤其是在我们身心获得全面发展所不可或缺的熟悉、亲密的领域。让我们表明我们的身份!每个人内心都有一个潜能的世界。我们要意识到自己的潜能,它和每个人的潜能一样,换言之,大多未被发掘,而且经常具有诗意,因此,是令人不安的。
不再有紧身衣,不再有现成的生活!不再有将我们数字化的数字建筑!不再有克隆城市,全球化的办公室,现成的家!我们希望能够继续旅行:聆听即兴演奏的音乐;体验承载着许多生活经验的景观;遇见创造他们文化的男男女女;发现陌生未知的颜色。建筑是变化的容器。建筑是不断遭到生命和事件渗透、更新的永恒。不可更改、从天而降的建筑,与所在地以及居住其中的人没有任何关联。
建筑必须被所在的地方和人所渗透,也要去对他们产生渗透:要具有强烈感受性,也要引起感动;要吸收,也要散发。让我们喜爱那些懂得如何聚焦的建筑:它如同光线一样闪耀;让你领略地形、大地的纹理;让你感受风、天空、土壤、水、火、气味、树、草、花、苔藓„„;记得地方风土人情、同时与我们世界的信息终端相联;还向我们呈现时代变迁以及穿越其间的人们。这样的建筑与它的时代和谐共处。仍在建造20世纪建筑范型的落后者染患了“历时”症、拒绝去感受他们的时代。建筑总是标注着日期。我们知道建筑终有一天会死的、是暂时存在的;我们知道它是有生命的。因此,我们看着它走出黑暗,并想像有一天它会回到那儿。
“因地制宜”、特殊的、具路易斯安那精神的建筑,在过去与未来、矿物与植物、瞬间与永恒、可见与不可见之间建立着一种联系。它们是显现与消失的所在地。它们不时暗示着自己缓慢而悲怆的毁灭。这个时间意识与居住其中的新生命所带来的惊奇,与黎明、黄昏的伟大节奏,以及不可避免的懒散和衰败时光所显露的无关紧要相重叠。具路易斯安那精神的建筑是梦中的建筑,是寂静无声的,既是遗忘之地,也是考古之地。它们成为对引发暖昧矛盾情绪的过去进行重新诠释的借口。
具路易斯安那精神的建筑令我们感动,因为它们被梦想出来,因为它们令人感到不安全、具反抗性;它们偶尔令人绝望、遇到灾难、或遭到扼杀,但从未被遗忘,因为正如凤凰浴火重生般,它们让我们想到用点线构成的永恒„„
武汉科技大学本科毕业设计外文翻译
具路易斯安那精神的建筑在材料和资源上的不确定性、简易性、甚至简陋性,滋生出这种建筑能够存在于各种经济环境的希望。基于这个原因,它可以渗透到任何地方,甚至包括我们的全球政治应该感到汗颜的贫民窟„„
武汉科技大学本科毕业设计外文翻译
Jean Nouvel’s LOUISIANA MANIFESTO is the most profound expression of histhoughts and ideas about architecture today.Together with his projects and shortfilm sequences,the text was part of an exhibition at the Louisiana Museum ofModern Art in Denmark that was shown from June 7th through September 18th,2005.It was published in many languages.Fundamental to his philosophy is anarchitecture that is alive,unique,specific and in harmony with its surroundingsand the spirit of the place.The exhibition was a collaboration between AteliersJean Nouvel,guest curator Jean-Louis Froment and the Louisiana Museum.(Noteby Verena M.Schindler)More than ever before in 2005 architecture is annihilating and violating places,making them banal.Sometimes the landscape is replaced,created in the image of the architectureitself,which is nothing but another way of effacing it.In contrast,however,there is the case of Louisiana,an emotional shock.The living proof of a forgotten truth:architecture has the power to transcend.Architecture can reveal geographies,histories,colours,vegetations,horizons,and qualities of light.Impertinent and natural,architecture is in the world,alive,unique,Louisianan.As a microcosm,a bubble,no image or statement can plumb its depth.You have to be there to experience and believe it.Architecture is an expansion of our world at a time when that world is gettingsmaller.At a time when we rush across the world faster and faster,when we listen to and watch the same global networks,share feelings aboutthe same disasters;when we dance to the same hits,watch the same matches;when we are flooded with the same films with their global screen stars;when the president of one country wants to rule the whole world;when we shop in cloned shopping centres,work behind the same eternalcurtainwalls...and,when whatever aspects of these factors that might be positive are notpartofglobalpriorities...Why,for instance,shouldn’t education eradicate illiteracy more quickly andsurely?Why doesn’t the medicine that saves the victims of pandemics get to them intime?Architecture is by no means spared of these new conditions of an efficient,profitableworld increasingly marked by an ideology delivered as the baggage of the economy.The global economy is accentuating the effects of the dominant architecture,the type that claims,‘We dont’ need context.’And yet there is no real debate about this galloping frenzy:invoking the limitsof the discipline architectural criticism is content with aesthetic and stylisticreflections devoid of any analysis of the real,ignoring the crucial historical clashthat-more insistently every day-sets global architecture against an architectureof situations,generic architecture against an architecture of specificity.Is our modernity today simply the direct descendant of the modernity of the20th century,devoid of any spirit of criticism?Does it simply consist of parachuting solitary objects onto the face of theplanet?Shouldnt’ it rather be looking for reasons,correspondences,harmonies anddifferences in order to propose an ad hoc architecture here and now?Louisiana is the symbolic arena for this new struggle of David and Goliath,between the partisans of situation architecture and the profiteers of de-contextualised architecture.Undoubtedly this confrontation runs deeper and is more complex than theissue of local against global.Specificity is linked to the actualization of knowledge.Architectural knowledgeis by nature diverse,given its links with all civilizations.Travel is an essentialelement in the cultivation of any builder.We are familiar with how journeys to Egypt,Greece and Rome are 武汉科技大学本科毕业设计外文翻译
importanttoarchitects.Louisiana is the result of a journey to California:the fruit of the graftingof information gathered from afar onto the interpretation of a uniquelocation.Generic architecture is certainly thriving on the compost,the Functionalistdroppings of the simplistic modern ideology of the 20th century.The AthensCharter set out to be humanist,but the equally dogmatic caricatures realized bythe submissive or the corrupt have left us with an oppressive urban heritage.In the name of the pleasure of living on this earth we must resist theurbanism of zones,networks and grids.Such developments are the automaticrot that is obliterating the identity of cities on all continents in all climates.These strategies feed on cloned offices,cloned dwellings and cloned shops.They thirst for what has already been thought and seen in order to avoidthinking and seeing.We must replace these generic rules,territorially and architecturally,withother rules based on the structural analysis of the lived landscape.Yes,architecturally!For architecture exists on all scales and urbanism does notUrbanism is nothing but the mocked-up travesty of a servile architecture on themacro-scale,advancing to prepare the way for the myriad of generic architectures.We must establish sensitive and poetic rules:approaches that speak of colours,essences,characters and the anomalies of the act of creation and the specificitiesof rain,wind,sea and mountains.Rules that speak of the temporal and spatial continuum that will turn the tidetowards a mutation modifying the inherited chaos and taking account of all thefractal scales of our cities.These sensitive rules cannot but defy the generic ideology that leads to theproliferation of hegemonic,dominant technologies.Creating dependencies andaimed for th‘ebottom line’,such a proliferation results in the hypertrophy of allour transportation,energy and hygiene systems.In contrast,the ideology of the specific aspires to autonomy,using theresources of actual place and time and such an ideology also privileges the non-material.How can we use what is here and nowhere else?How can we differentiate without caricaturing?How can we achieve depth?Architectural design on the large scale does not mean inventing ex nihilo.Architecture means transformation,organizing the mutations of what is alreadythere.Architecture means encouraging the embedding in the landscape of places thatanyway have a tendency to invent themselves.It means to reveal,to give direction.It means prolonging living history and its traces of past lives.It means listening to the breathing and pulsations of a living place.It means interpreting its rhythms in order to create.Architecture should be seen as the modification of a physical,atomic andbiological continuum.As the modification of a fragment situated at the heart of our immenseuniverse amidst the dizzying discoveries made by macro-and nanophysics.Whatever the scale of the transformation of a site or place,how can wecommunicate the unpredictability of the mutation of a living fragment?Can we domesticate the visible components-clouds,plant-life and livingorganisms of every size-with signs,reflections and new plantings?How does one create a vibration that evokes a hidden depth,a soul?This is surely a task for poetry since only poetry can produce‘the metaphysicsof the instant’:to work at the limits of the achievable with the mysterious,fragile and natural;to anticipate the weathering of time,i.e.,the resulting patina as materialschange and age with character;andto work with imperfection as a revelation of the limits of the accessible.These architectures that kill emotion are not Louisianan.They are the 武汉科技大学本科毕业设计外文翻译
work of globetrotting artist-architects,princes of repetition,specialists in the perfect,dry and perennial detail that are the true confession ofemotional impotence!The repetition of the‘controlled’detail is proof of their insensitivity to thepossible nature of an architecture in the world.Mass construction is used as misconstruction!Weight and emphasis are understood as vectors of architectural pedantry!The detail-like the totality-is an opportunity to invent,dislocate,enrichthe world,recompose,reassemble and provoke confrontations of textures,lightand unlikely techniques.But generic detail,like generic architecture,manifests the prefabricated.Itrepresents an absence of doubt that takes no risks and holds back as far as possiblefrom the limits of the feasible and sensitive.Its vocation is to exist and sell itselfeverywhere,spreading uniformity and killing differences in order to proliferate.We are in the domain of simplistic thinking-of the systemic,the reassuring.We are far from the sine qua non of seduction:the natural.An architecture that creates singularity in duality and is invented through theconfrontation with a situation is Louisianan.It opposes the attitudes of these artist-architects who follow a recipe ofrepeating a kind of formal order passed off as the‘signature of the artist’.Itopposes what can be dropped down on the landscape on any occasion in any place.This global phenomenon perpetuates an artistic tradition of the 20th centuryart that is in essence unsituated,dislocated and designed to take its place amongthe mathematical white boxes of the museums.Unlike these works of art that can function in isolation,autonomousarchitectures are doomed to the status of static interference,absurd collages andsudden sneezes that disturb their surroundings;and unfortunately Surrealistsensibility is rarely part of the mix...Architecture means the adaptation of the conditions of a place to a given timeby the willpower,desire and knowledge of certain human beings.We never do this alone.We always do it somewhere-certainly for some person or persons,butalways also for everyone.It is time we stop limiting architecture to the appropriation of a style.Our times need architects who doubt,who seek without thinking they havealready found,who put themselves at risk,who rediscover the values of empiricism,who invent architecture as they design it,who surprise themselves,who notice themildew on their windows and who know how to interpret it.Lets’ leave the cosmetics of vain cities to the architects who think of themselvesas aesthetes.From now on let architecture rediscover its aura in the inexpressible,thecloudy and imperfection of what is invented!The architect is not aware of having come to the end of his work until he slipsand shiftsfrom creation to modification,from assertion to allusion,from building-up to filling-in,from construction to infiltration,from positioning to super-positioning,from clearness to the nebulousness,from addition to deviation,from calligraphy to etching,to erasure...Instead of the archaic architectural goal of domination,i.e.,making a permanentmark,today we should prefer to seek the pleasure of living somewhere.Let us remember that architecture can also be an instrument of oppression,atool for conditioning behaviour.Let us never permit anyone to censure this pursuit of pleasure especially in thedomain of the familiar and intimate that is so necessary to our wellbeing.Let us identify ourselves.Everyone bears a potential world within himself or herself.Let us be aware of our potential,which is equal to that of any human being-largely unexplored,often poetic and therefore disquieting.武汉科技大学本科毕业设计外文翻译
No more corsets,no more ready-to-wear lives!No more architecture-by-numbers that turns us into numbers!No more cloned cities,global offices,pre-occupied homes!We want to be able to keep on travelling:to listen to spontaneous music,to live in landscapes as inhabited as a personalityto meet men and women who invent their own culture,to discover unknown colours.Architecture is the vehicle for variations.Architecture is permanence changed by life and events.Unchangeable architecture is not involved with the place and those who livethere.Architecture has to be impregnated and to impregnate in order:to be impressionable and impress andto absorb and emit.Let us love architecture that knows how to focus,that:shineslikealight;can let you read the topography,the lay of the land;can let you feel the wind,sky,soil,water,fire,flavours,trees,grass,flowers,moss...remembers the usages and customs of the place and at the same timeinterfaces with the information terminals of our world;and,shows us the historical ages and those who have journeyed through them.Such an architecture is built up in harmony with its time.The stragglers whoare still constructing the archetypes of the 20th century are diachronically ill,refusingtolivetheirlives.Architecture is dated.We know it to be mortal and endangered as sure as weknow it is alive.And so we watch it emerging from the darkness and imagine that it will returnthere one day.The architectures of situation,of the specific,the Louisianan architecturesweave bonds between the past and the future,the mineral and the vegetal,theinstantaneous and eternity,and the visible and the invisible.They are the loci of emergence and disappearance.They distil the essence of their own slow,poignant ruin.This consciousness of time overlays the surprises of the new lives lived in theplace,the great rhythms of dawn and twilight,the indifference of the inevitablehours of idleness and decay...Louisianan architectures are dreamed architectures,full of silences-notonly places of forgetfulness but also of archaeology.They become the cue for reinterpretations of an ambivalent past.Louisianan architectures move us because they have been dreamed into life,insecurity,resistance and sometimes despair;ruined or assassinated,but neverforgotten because like the Phoenix disappearing in the flames only to be rebornthey make us dream of eternally recurring points of light...The uncertainty,simplicity and even the modesty of the Louisianan materialsand resources hold out the hope that Louisianan architecture can continue toexist in any economic condition even filtering through to the shameful shantytownsofourglobalpolitics...
第三篇:1300外文文献翻译
Agricultural Land and Regulation in the Transition Economy of Russia Ekaterina Gnedenko1 & Michael Kazmin2 Published online: 7 July 2015 # International Atlantic Economic Society 2015 JEL Classification C10.L33.O57.Q00 This research note explores the link between farmland conversion and existing land regulation in Russia.We conclude that land regulation is lagging the new market trends in the transition economy of Russia.As market forces continue to penetrate the economy, apparent managerial and statutory problems with regard to local land-use planning and regulation preclude more effective use of land.Responding to the need for attracting investment in agriculture, the Russian Ministry of Science and Education provided funds for our research project that involves primary data collection and econometric analysis of the interdependencies between governmental policies and farmland loss.Our unique dataset contains socioeconomic, demographic and spatial geographic 2010 data for 39 municipal districts in the Moscow metropolitan region.The econometric analysis of this data set is used to explore the relationship among farmland quantity, its assessed value, the share of privatized farmland, farmland tax,and land-use zoning in the simultaneous equations framework.While the Russian market for real estate has developed quickly, the market for agricultural land is still thin.Farmland deals are limited, partly because of the lingering uncertainty about farmland property rights.The state-owned farmland is still significant.Our Moscow regional data suggest a strong positive relationship between the fraction of privatized farmland and farmland acreage, although the fraction of individually and collectively privatized farmland is only 57 %.The direct sale of farmland to foreigners is prohibited decreasing potential foreign investment as well.As a result, the area occupied by agricultural lands has been steadily decreasing and deteriorating in quality.During the period 1990 to 2005, tillable lands in Russia have shrunk by 10.5 million hectares(7.9 % of tillable lands).Lacking experience and adequate knowledge, local governments are stuck with the land conservation policies available to the former USSR.In particular, in an attempt to contain the loss of prime farmland, the regulators retain old land-use zoning laws prohibiting the change of land status.However, strong development pressures and widespread corruption often annihilate the desirable effect of zoning.The results of our econometric analysis indicate that the proximity to Moscow city and population growth both have a significant negative effect on the amount of farmland, even in the strictlyzoned-for agriculture districts, suggesting strong urban pressure in the capital region of Moscow.The estimated elasticity of farmland acreage with respect to population growth is −0.3.A corrupt practice of illegal changes in land status is reflected in the fact that the lands still classified as farmland in the Federal Register of Land are turned into residential or industrial areas.This signals a management problem which could be perhaps resolved by the introduction of more flexible zoning and an increase in the range of responsibilities of local governments and their property rights to land.The other economic instrument indispensable in land policy, land assessment, is also based on the former practices of the Communist period following a federally mandated general formula that takes into account soil productivity criteria, topographic features of the landscape, and the presence of irrigation, but still has little in common with the market price of farmland.When the agricultural land tax is calculated as the percentage of the assessed value of farmland, which is often below its real market value, local authorities are not interested in developing local agricultural infrastructure or increasing agricultural land base because they will not be able to reap any significant tax benefits from it.Coupled with the low federally mandated upper limits on tax rates(0.3 % of the assessed value of agricultural and residential lands)this leads to insufficient local tax revenues and overreliance on intergovernmental transfers.According to our data for the Moscow region, although localities tend to impose the maximum allowable tax rate, the average share of land tax revenues in local budgets is a mere 5 %.It is not surprising as the average assessed value of farmland across municipalities is 1000 times less than the ongoing average sales price, according to data we collected.The insignificant local land tax revenues caused by the underestimated land value lead to insufficient local infrastructure investment, which further suppresses the value of farmland and hastens its conversion.The results of the econometric analysis indicate lack of statistical significance between the assessed value of farmland and farmland quantity in the Moscow region, making the farmland tax rate an ineffective instrument in land policy.This missing link between the farmland quantity and existing land policies may render these policies not just ineffective but even wasteful.Innovative approaches such as the retention of development rights by the government might represent a temporary solution.The increasing reliance on local governance in solvinglocal problems would imply improved land-use and public finance planning and,perhaps, a slower farmland conversion trend.俄罗斯经济转型中的农业用地与监管
Ekaterina Gnedenko1 & Michael Kazmin2。在线出版:2015年7月7日。国际大西洋经济学会2015。冻胶分类C10。L33。O57。Q00 本研究报告探讨了俄罗斯农地转换与现有土地规制之间的关系。我们的结论是,土地监管滞后于俄罗斯转型经济的新市场趋势。由于市场力量继续渗透经济,在地方土地利用规划和管理方面显然存在管理和法律问题,妨碍了更有效地利用土地。为了应对吸引农业投资的需要,俄罗斯科学和教育部为我们的研究项目提供了资金,该项目涉及对政府政策和农田损失之间相互依赖关系的主要数据收集和计量分析。我们独特的数据集包含社会经济、人口和空间。2010年莫斯科都市地区39个市辖区的地理数据。通过对该数据集的计量分析,探讨了在联立方程框架下,耕地数量、其评估值、私有化耕地占比、农地税和土地利用区划之间的关系。
虽然俄罗斯房地产市场发展迅速,但农业用地市场仍很薄弱。农田交易是有限的,部分原因是土地产权的不确定性挥之不去。国有农田仍然很重要。我们的莫斯科地区数据显示,私有化耕地和耕地面积的比例之间存在着强烈的正相关关系,尽管单独和集体私有化耕地的比例仅为57%。禁止向外国人直接出售农田,也禁止减少潜在的外国投资。因此,农地占用的面积一直在稳步下降,质量也在不断恶化。在1990年至2005年期间,俄罗斯的可耕种土地减少了1050万公顷(占耕地面积的7.9%)。
由于缺乏经验和足够的知识,地方政府只能依靠前苏联提供的土地保护政策。特别是,为了遏制主要农田的流失,监管机构保留了禁止改变土地状况的旧土地用途分区法。然而,强大的发展压力和广泛的腐败往往会消灭分区制的理想效果。我们的计量分析结果表明,靠近莫斯科城市和人口增长对农田的数量有显著的负面影响,即使是在严格的农业地区,这表明莫斯科的首都地区的城市压力很大。在人口增长方面,耕地面积的估计弹性为0.3。非法改变土地状况的一种腐败做法,反映在土地仍然被归为联邦土地登记册上的土地的土地被转变为住宅或工业区的事实。这标志着一个管理问题,也许可以通过引进更灵活的分区和增加地方政府的责任范围和土地的财产权来解决。
其他经济工具不可或缺的土地政策、土地评估,也是基于前实践后共产主义时期的联邦法律规定的一般公式,考虑土壤生产力标准,地貌景观的灌溉的存在,但仍然没有与市场价格的农田。农业土地税计算时的评估价值的百分比农田,这通常是低于其实际市场价值,当地政府发展当地的农业基础设施不感兴趣或增加农业用地基地,因为他们将无法获得任何重大税收优惠。再加上联邦政府规定的低税率(占农业和居住用地评估价值的0.3%),这将导致当地税收收入不足,并过度依赖政府间转移。根据我们对莫斯科地区的数据,虽然地方倾向于征收最高允许的税率,但地方预算的土地税收收入的平均份额仅为5%。据我们收集的数据显示,由于各城市的农田平均分摊价值比目前的平均销售价格低1000倍,这并不令人惊讶。
由于土地价值被低估而导致的地方土地税收不显著,导致地方基础设施投资不足,进一步抑制了农田价值,加快了土地流转。经济计量分析结果表明,在莫斯科地区,耕地和耕地数量的评估价值缺乏统计意义,使得农地税率在土地政策中是无效的。耕地数量和现有土地政策之间缺失的联系可能使这些政策不仅无效,甚至是浪费。政府保留发展权利等创新办法可能是一种临时解决办法。在解决地方问题上日益依赖地方治理,将意味着改善土地利用和公共财政规划,也许还会减缓农地转换的趋势。
第四篇:外文文献翻译译文[定稿]
在激光作用下核压力容器钢焊接接头的显微组织和力学性能
摘要:设计间接热冲压工艺,利用有限元法对零件的几何尺寸和力学性能进行了预测。在间接热冲压过程的情况下,生产性能与适应车身部件,冷却路径造成扩散和扩散控制的相变。通过人脸的相变引起的体积膨胀为面心立方(FCC)为体心立方(BCC)和体心四方(BCT)马氏体的形成导致相变诱导株的整体应力热冲压的车身部件的计算是很重要的。计算的应力和应变状态正确,它是必要的模型的扩散和扩散控制的相变现象,考虑到间接热冲压过程的边界条件。现有的材料模型进行分析和扩展以提高计算铁氧体、珍珠岩的数量和分布,其预测的准确性,整个退火过程中贝氏体和马氏体。工业用新方法在有限元程序LS-DYNA 971实现
关键词: 核钢
稳压器 压水反应堆 反应堆压力容器 结构完整性 焊接韧性
SA508钢通常用于民用核反应堆的关键部件,如反应堆压力容器。核部件通常采用电弧焊接工艺,但与设计为未来的新建设项目超过60年的生活,新的焊接技术正在寻求。在这种探索性的研究,为第一时间,自体激光焊接6毫米厚的进行SA508 Cl.3钢板使用16千瓦激光系统在4千瓦的功率运行。这个
显微组织和力学性能(包括显微硬度、抗拉强度、延伸率等夏比冲击韧性)的特点和结构进行了比较电弧焊接。基于移动体热的三维瞬态模型源模型也发展到模拟激光焊接热循环,以估计冷却速率的过程。初步结果表明,激光焊接工艺可以无宏观缺陷的焊缝,激光焊接的强度和韧性在这项研究中的联合,得到的值,在焊接的母材条件。
反应堆压力容器的寿命和安全运行(RPV),这是核电站中最关键的部件之一。取决于高温压力容器材料的耐久性,高压力和放射性环境。具有较高强度,韧性和抗辐照脆化的材料的需要是上升的,由于增加的发电容量和核电厂的设计寿命[ 1 ],[ 2 ],[ 3 ],[ 4 ],[ 5 ],[ 7 ],[ 8 ]和[ 6 ]。SA508钢已经用于许多RPV?的压水反应堆制造因为他们提供的结合强度,延展性好,断裂韧性,相对于机械性能的均匀性,和他们的经济[ 9 ]、[ 10 ]、[ 11 ]和[ 12 ]。无人机是采用焊接厚环形锻件或SA508钢板在一起。这些通常是采用电弧焊接实现,其次是为焊后热处理以恢复在热影响区(HAZ)韧性。而电弧焊接技术以及建立这些组件,在高功率激光器的可用性增加,能够以较高的焊接速度,减少焊接变形中厚截面钢,提供激励考虑激光焊接焊接部件制造SA508钢提供任何优势.传统的焊接方法制造的核压力容器用钨极氩弧焊(GTAW)和埋弧焊(SAW)[ 13 ]、[ 14 ]和[ 15 ]。在版本óN et al.?的[ 14 ]研究评估应力释放在HAZ裂纹敏感性,多次看到来为每一个通过1.8 kJ /毫米的热输入焊接140毫米厚的SA508 2级钢。基姆等。[ 16 ]报道常规看到3 kJ /毫米每通过一个热输入SA 508级3钢的焊接。Murty等人。[ 13 ]发现,多通过SA533B钢埋弧焊接,焊缝金属的热影响区宽度,分别为26和12毫米,分别。locsdon [ 17 ]焊接64毫米厚的钢板SA533组环境2使用多道窄间隙钨极氩弧焊用10毫米宽的槽和1.6 kJ /毫米每通过一个热输入。可以看出,这些传统的焊接技术相比,激光焊接一般采用较高的热输入,这会增加热影响区宽度和焊后导致更大的扭曲和较高的残余应力。这将是复合的,如果更多的焊接通道和添加更多的填充材料是必需的,由于就业的更广泛的焊接槽,这些因素也可能有助于增加生产成本。
与传统的焊接技术相比,激光焊接具有其自身的优势,高功率密度等,以及相关的能力,具有窄的热影响区做一个窄的焊缝,采用较低的热输入和焊接速度高,达到较低水平的残余应力和变形,同时消耗更少的填充材料[ 18 ]和[ 19 ]。此外,激光焊接可以实现使用远程控制,因为激光束可以使用光纤和焊接头可以安装在一个工业机器人。这种特性使得激光焊接适合生产高质量的焊缝,所需的核环境。事实上,激光焊接到中等厚的部分奥氏体不锈钢的应用已经探讨过。张等。[ 20 ]首先报道了8毫米厚的316毫米厚的50毫米厚钢板的窄间隙焊接。elmesalamy等人。[ 21 ]成功焊接了20毫米厚的316不锈钢使用1千瓦IPG单模光纤激光器的超窄间隙(1.5 mm间隙宽度),双方采用多道窄间隙焊接的方法。尽管如此,没有被报道在SA508钢激光焊接特性。
在低合金钢焊接过程中发生的固态相变可能是非常复杂的,在某些钢中,它可以很难预测焊接接头的不同子区域的组织结构。冷却速率在不同的子区域将确定相变发生在连续冷却转变组合焊接过程中(CCT)在调查中对钢图。在焊接过程中的温度历史可以记录使用热电偶。然而,热电偶只能测量离散点的温度历史。它也很难保证测量位置的温度可以正确地记录下来。有限元建模是一种替代的方法,在焊接过程中的热循环调查。
在本研究中,单次自体激光焊接是参加SA508条款3钢板。自体GTA焊接的开展提供这种钢的激光焊接的基准。显微组织和力学性能,如拉伸强度、硬度、和在焊接条件下研究了冲击韧性的焊接构件。基于移动体积热源模型模拟也进行了量化的焊接热循环对微观结构的变化在自体激光焊接在SA508钢的影响。数值的解决方案是使用商业软件ANSYS生成,并与实验结果进行了比较,验证了数值模型。验证的模型,然后用于预测的激光焊接的热历史。本文介绍了实验和建模,并报告了这项工作所产生的初步结果。2。材料与实验程序
作为收到的基体材料(BM)在这项研究中使用的是调质SA508 Cl.3钢。SA508条款3钢的化学成分如表1。碳当量(CE)是一个参数,通常用于评价钢的焊接性,它被定义为合金元素除碳的碳当量浓度的百分比,从钢的淬透性的观点。根据参考文献[ 22 ]计算调查的钢的CE,并给出:
从表1看出,SA508 CE 0.60。MS(马氏体转变开始温度在420 C)°根据铃木?的连续冷却转变曲线(CCT)508级3图。条款1钢[ 23 ]。AC1和Ac3温度约700°C和800°C,分别。光学显微镜和扫描电子显微镜(SEM)对基地SA508钢的显微组织图像都显示在图1(a)和(b),分别。标本机械抛光和蚀刻在2%硝酸溶液。基体材料的微观结构(BM)是一个暴躁的上贝氏体结构。细小的析出物由不同的研究人员已经确定,他们是M7C3和M23C6 [ 6 ]、[ 12 ]和[ 24 ]。
作为收到SA508 Cl.3块切成几个6毫米和2毫米厚的板线放电加工(EDM)焊接试验。自体激光焊接材料的尺寸大约是6毫米,100毫米和50毫米××手动自体GTA焊接约2毫米50毫米100毫米××。
实验使用连续波光纤激光器进行(IPG yls-16000)与一个16千瓦的最大功率。光束参数乘积为10毫米毫弧度的处理纤维300μ米直径。从光纤的一端发射的激光束被准直由一个150毫米焦距的镜头,然后聚焦到试样表面用镜头用400毫米焦距。测得的聚焦尺寸和瑞利长度分别为0.8毫米和15毫米,分别。激光头安装在一个六轴库卡机器人。激光焊接的示意图如图所示。
350 GTA焊接电源是用于手动自体GTA焊接实验。在焊接前,样品被喷砂去除氧化物层。喷砂处理后,用丙酮清洗表面,然后将基体材料固定,以保证充分的约束。自体激光焊接和点焊进行。在焊接过程中保护熔池,用氩气保护试样的顶部和背面。
焊接接头的宏观结构和焊缝的微观结构是利用光学金相显微镜检查(KEYENCE vhx-500f)和飞利浦XL 30扫描电子显微镜(SEM)。表面硬度测量使用Struers duramin-2维氏显微硬度计进行。
在焊缝的显微硬度分布进行测量,分别位于顶部,在激光焊接接头的宏观截面中部和底部,并在焊接在板厚中间位置为手动GTA焊接接头。使用负载3公斤,停留一段时间10 s的维氏显微硬度机测试硬度(Struers duramin-2)。三测量每个缩进以最小化误差进行。硬度遍历进行跨焊缝在0.2毫米在熔合区和热影响区间隔的凹槽,并在BM 0.4毫米的间隔。
对接收的母材和焊接试样的静态拉伸强度评价标本根据ASTM E8M-04产生。子尺寸夏比冲击试验样品的制备在BS EN 10045-1:1990意图。缺口位于熔合区,以测试激光焊接样品的焊接金属的韧性。这些冲击试样的宽度是由板块焊接厚度的限制,即6毫米。每一个测试是重复的三个单独的和名义上相同的优惠券,以减少不确定性。夏比和交叉焊缝拉伸试样从电火花加工过程中使用的焊接稳定状态的区域提取。所提取的样品的基体材料和焊接样品的大小和形状如图3所示。焊接钢筋的脸和根部焊缝试样的地区由手工打磨砂纸在拉伸和夏比冲击试验进行删除。进行拉伸试验在Instron 4507号模型电子万能试验机在室温下。夏比冲击试验的基础材料和焊接的样品上进行兹维克Roell夏比冲击试验机在?40°C,?20°C、0 C和°室温。每一张优惠券在测试前的半小时内举行相关的测试,以确保整个样品的温度均匀一致。以下的拉伸强度和冲击韧性试验,所有的断裂面测试标本用Zeiss EVO 50 SEM设有X射线能谱仪(EDX),研究了断口形貌和确定断裂模式。
最初的试验进行了使用珠的板的配置,而不是加入两个不同的板,以优化焊接参数。的激光功率为4千瓦,选择和焊接速度从0.84米/分钟到1.08米/分钟不等。激光焦点设置在板的顶部表面的2毫米。使用氩气保护气体,气体流速为12升/分钟和8升/分钟,分别保护使用的顶部表面和在焊缝侧的焊缝。激光头由8个倾斜倾斜,以防止反射。
焊接后,焊缝被切割,并准备作为金相样品,以评估焊接珠的完整性。在图4中给出了不同焊接参数的结果。
检查的焊接参数的不同的焊接参数显示,可以接受的焊缝轮廓,实现与焊接速度为0.84米/分钟,0.96米/分钟,在顶部的焊缝金属区域的切边观察到1.02米/分钟的速度,并观察到在一个速度为1.08米/分钟。优化的焊接参数在表2中概述。自体激光对接焊接6毫米SA508钢采用这些优化的焊接参数进行。
350 GTA焊接电源是用于焊接2毫米厚的钢板508。手动自体GTA焊接进行提供最好的比较自体激光焊接。与2毫米的厚度板被用在GTA焊接固有的浅层渗透,双面焊接进行了。焊接参数在表3中概述。
3。结果
3.1。宏观结构特征
SA508钢焊接接头的自体激光对接结构,采用优化的参数,如图5所示。可以看出,焊缝两侧的熔合线几乎是平行的,这是小孔焊接的特点。没有任何证据的缺陷,如孔隙度或削弱。焊缝的宽度约为1.8毫米,和热影响区的宽度大约为0.8毫米。接头可以分为几个不同的区域,如冶金,熔合区(FZ)在中心,热影响区(HAZ)与基体材料(BM)。熔合区由粗大的柱状枝晶颗粒组成,其与垂直于熔合边界的方向对准。最大热流方向为垂直于熔合边界,晶粒趋向于向上生长最快,在熔合区内的柱状晶组织中有25和26。在光学显微镜下,它被观察到的晶粒尺寸随距离从焊缝中心线。焊接热影响区可进一步划分为三个不同的区域:粗晶热影响区(CGHAZ)(靠近熔合线),细晶热影响区(FGHAZ)和两相区(ICHAZ)相邻的BM。
一个宏观部分通过手工自体GTA焊接2毫米厚的SA508钢如图6所示。由于有限的穿透深度在GTA焊接,双面自手动GTA焊接应用。熔合区的宽度约为2.4毫米,和热影响区的宽度大约为2.8毫米。在熔合区和热影响区宽度大于6毫米厚的激光焊缝宽得多。
3.2。微观结构特征
焊接接头各子区域内的显微组织演变主要由焊接热循环过程中的峰值温度和每个相应的子区域的冷却速度[ 27 ]和[ 28 ]确定。作为焊接结构在6毫米厚的激光焊接2毫米厚的手册进行自体GTA焊接熔合区和在每一个不同的子区域内的热影响区(CGHAZ,FGHAZ ICHAZ)使用SEM结果在图7和图8分别给出了。对焊接工艺的焊接热影响区内的不同子带的结构是相似的。然而,更细小的析出物在GTA焊接热影响区的发现相比,激光焊接接头。在基姆等人的工作中。[ 29 ]和[ 30 ],细小的析出物被确定为高钼含量的M2C型碳化物。在焊缝,包括贝氏体组织在ICHAZ,marteniste和自回火马氏体。在FGHAZ组织包括汽车回火马氏体细晶粒马氏体。在粗晶区,显微组织由马氏体和回火马氏体粗粒度的汽车,而在融合区,粗大的马氏体和自动观察回火马氏体。3.3。显微硬度
作为焊接的显微硬度分布在激光焊接和手动GTA焊接如图9。可以看出,无论是激光在焊缝及热影响区的硬度(~ 430 HV0.3)和多伦多(~ 410 HV0.3)焊接试样高于基体材料的两倍(~ 200 HV0.3)。这是预期的焊接条件下的焊接。在熔合区的硬度略高于激光焊接试样的焊接热影响区。为GTA在熔合区和热影响区的硬度,焊接接头在410上下波动,峰值硬度HV0.3,发生在FGHAZ约430 HV0.3。在激光熔合区和热影响区的硬度焊接接头(~ 430 HV0.3)高于熔合区的GTA焊接接头(~ 410 HV0.3)。
3.4。室温拉伸行为
交叉焊缝的拉伸数据如表观屈服强度参数,拉伸强度和伸长率均明显,2毫米厚的钨极氩弧焊试样和6毫米厚的激光焊接试样总结在表4中,其中包括平均值和标准偏差。应该牢记的是,试样显然是不均匀的,因此,记录的屈服强度和伸长率的值是不真正代表任何特定的微观结构区,并且它们也将随选择的规范长度(在这种情况下,25毫米)。尽管如此,在这项研究中,测得的值被包括提供一个定性的比较,每个焊缝。明显的屈服强度(YS)、抗拉强度(UTS)和明显的伸长量估计为494 MPa、631 MPa和26.3%,对于6毫米厚的激光焊接试样。所有的拉伸破坏发生在远离焊接区域的。YS,为6毫米厚的基底材料的抗拉强度和延伸率分别为498 MPa、632 MPa和28.1%,分别。相比较而言,明显的屈服强度(YS)、抗拉强度(UTS)和2毫米厚的钨极氩弧焊试样明显伸长估计为498 MPa、633 MPa和17.1%,分别。所有的拉伸破坏发生在远离焊接区域的。YS,为2毫米厚的基底材料的抗拉强度和延伸率分别为501 MPa、633 MPa和19.3%,分别。
裂缝性的标本在图10。所记录的应力-应变曲线的基本材料和焊接试样的厚度为2毫米和6毫米,如图11所示。它可以从拉伸试验结果表明,激光和GTA焊接试样的拉伸性能有非常相似的基础材料在相应的厚度。然而,焊接试样的表观伸长率略低与那些相应基础材料相比。在图9中的硬度分布表明,在焊接条件下,焊接过程中所产生的材料已加强,所以很可能在拉伸试验过程中,焊接区域没有产生屈服,从而有助于降低延伸率。此外,它可以从拉伸试验结果表明,材料的厚度对屈服强度和断裂强度几乎没有影响,与2毫米厚,6毫米厚的材料呈现类似的屈服强度和断裂强度。令人好奇的是,材料的厚度,有一个显着的影响的伸长率,与较薄的材料(2毫米厚)提出较低的伸长率时相比,与6毫米厚的材料。
3.5。夏比冲击韧性,以不同的temperatures 《能源吸附的碱金属和焊缝的激光冲击下的冰plotted作为一个功能的温度在图13。《子尺寸试样断裂后shown夏比冲击试验是在图14。它可以看到,所有的paths破碎的激光焊接试样的试验开始的,然后deviate熔合区和HAZ的基体材料。测试结果的基础材料是repeatable,当测试结果的激光焊接试样的显着为低散射的测试temperatures(?40°C和?20°C),这可能是attributed的偏差,在断裂的裂纹。为了highlight的散射的结果对激光焊接specimens,这三个测试的结果是市场在每个温度图13和图14。许多研究人员已经reported,激光和电子束焊接过程中可能对目前的困难owing韧性试验区的两个窄融合在一起,有一个大学学位的高强度的高匹配接头[ 31 ],[ 32 ],[ 33 ]和[ 34 ]。reported倾向,艾略特的《deviate断裂成两个基地,而不是金属的熔合区propagate通CAN导线的两个结果misleading [ 35 ]
基本材料的结果显示一个整体的趋势:所吸收的能量的增加,在测试温度的增加。相比之下,激光焊接的结果中的散射意味着任何这样的趋势是不明显的。基础材料达到良好的韧性,吸收的能量与平均值约为70 J,95 J,97 J和105 J在?40°C对应的试验温度,?20°C、0 C和23 C°°,分别。它可以发现从夏比冲击试验结果的平均吸收的激光焊缝试样的能量相媲美的基础材料。对于激光焊接试样的平均吸收能量值分别约为92 J,80 J,100 J和98 J在?40°C对应的测试温度,?20°C、0 C和23 C°°,分别。然而,有孤立的低能量吸收值66 J在?40°C和45 J在?20°C为激光焊接的试样,但在这些温度约100 J这些孤立的低韧性值贡献了大量分散在吸收能量值的激光焊接试样在测试温度低平均值。
基体材料的宏观断口和激光焊接试样的冲击试验后如图15。为基料在?40°C测试(图15(a)),可以看出,裂纹传播从最初的韧性缺口之前继续通过脆性断裂试样的传播。韧性断裂的区域和随后的脆性断裂的区域之间的边界清楚地是在图15(1)。的脆性断裂区域跨越约60%的断裂面作为一个整体。激光焊接试样断裂在?40°C(图15(b))揭示了非常不同的两个断裂面:左边的样本提供了一个完全的韧性断裂表面实现了高吸收的能量(102 J),而右边的样本显示,裂纹开始传播之前的韧性继续传播在脆性的方式在大多数(~ 60%)的断裂面,和吸收的能量明显低于这个标本(66 J)。断裂的基础材料试件在?20°C完整呈现韧性断裂面在图15(c)。激光焊接试样断裂在?20°C测试(图15(d))又提出了两种非常不同的断裂面:左边的样本提供了一个完全的韧性断口(84 J),而右边的样本揭示了一个完全脆性断裂面(45 J)。在0°C和室温下测试的基本材料和激光焊接试件在所有剩余的情况下,如图15(电子)-(小时),在所有剩余的情况下,完全韧性断裂面。
断口的基体材料和激光焊接试样的冲击试验后,在图16中所示的高放大倍率。解理断裂被证实在这些基础材料和激光焊接试件的断裂与低吸收的能量在?40°C.对断裂的脆性解理断裂面显示为主和少量的韧窝(图16(a)和(c))。相比之下,激光焊接的试样,获得更高的能量吸收在?40°C显示韧性断裂表面的等轴韧窝(图16(b))。在?20°C,无论是基础材料和激光焊接的试样,达到更高的吸收能量呈现韧性断裂表面的等轴韧窝在图16(d)和(e),而较低的能量吸收了由解理断裂表面的激光焊接试样(图16(f))。所有基础材料和激光焊接试样在0°C,在室温下呈现韧性断裂的等轴韧窝在图16(g)–(J)。
3.6。三维有限元建模的自激光焊接工艺的制定和程序
这是理解激光自熔焊接SA508钢时的微观组织演化研究焊接过程的温度场的重要,这是特别是在焊接热影响区的情况。在构建一个数值模型来预测在不同的子区域的热历史,在焊接过程中,下面的假设,以简化的解决方案[ 36 ]:(1)
材料是各向同性的,并且环境温度和初始试样的温度均为20(2)
焊接熔池中液态金属的对流流动和小孔激光焊接中的汽化现象,可以忽略。(3)
在焊接过程中的热流量是由传导和对流的影响,即辐射的影响可以忽略。此外,在试样和环境之间的界面处的对流系数可以被假定为常数。(4)
由于焊接接头的对称性,可以应用于对称性,因此,只有必要的模拟焊接接头的一侧。
模型尺寸为50毫米,50毫米,6毫米。图17显示了网格配置。在三维实体模型,利用ANSYS软件生成的38337个节点和41040个单元(12.1版)。细网格中的熔合区附近的热影响区,陡峭的温度梯度可以预期,而较粗的网格被用来进一步远离焊缝和热影响区的坡度可能没那么严重。此外,随着距离的增加,元件的尺寸逐渐增大,最小的单元尺寸为0.5毫米0。5毫米0.5毫米。在这个模型中,X轴对应的焊接方向,Y轴是正常的焊接方向但在板的平面,和Z方向的平
面外方向。
使用温度依赖性的热性能进行热分析。瞬态温度,吨,被确定为一个函数的时间,吨,和空间(×,),通过求解下面的传热方程[ 37 ]和[ 38 ]
在这里,K(t)的热导率为在1 K W M??1温度的功能,ρ(t)是密度为3的魔芋葡甘聚糖?温度功能,CP(T)是在恒定的压力作为一个J 1 K 1公斤??温度函数的具体热,和QV是WM-3容积热通量 高功率激光束是一个高度集中的热源,热源模型通常用于在激光束焊接的数值分析中的各种穿透深度的功率密度的变化。在许多论文[ 39 ],[ 40 ]和[ 41 ],热源被假定为高斯分布的形式,但它通常是在实验研究的基础上修改。有一个公认的“钥匙孔”现象[ 39 ],[ 42 ]和[ 43 ],其中一些激光功率被吸收的离子蒸汽在钥匙孔,并转移到焊接熔池表面,这也是“小孔”边界。因此,一个体积热源模型通常用于模拟激光焊接过程。在体积热源模型,高斯热通量分布往往假定在径向方向和“钥匙孔”被认为是一个圆柱体或截断锥[ 39 ]。在本次调查中,一个旋转抛物面体积热源的温度场模拟。配电遵循高斯热流分布在每一层的旋转抛物面。热源可以被描述为[ 44 ]
其中,Q为旋转抛物面体积热源点的功率密度,并在热源效率,η,被认为是在热分析[ 38 ] 80%,泽是纵坐标上的parboloid最大的可能值,子是这个垂直坐标的最小可能值,H是抛物面的高度,再是抛物面的开口半径R0的抛物面的任何一点的半径,r是距离内任意点旋转抛物面体积热源的热源中心,P是输出的激光功率和Z是在平面方向坐标,相对于板,模型中的任何一点。所使用的材料的热物理性能的文献[ 45 ] 在热分析过程中,对流边界条件适用于所有自由表面的模型,除了对称的平面,其中一个绝热边界条件。方程(4)给出了模拟中的热边界条件。
在这里,T和T0在板被焊接的表面温度和环境温度,分别。空气的对流换热系数,hconv被假定为15周长1.2米 [ 38 ]。
为了验证模拟结果,无论是实验测得的热循环和熔合区形态进行了比较与那些从模拟所产生的预测。连续测量整个焊接过程采用K型热电偶在激光焊接试样的热循环。一个squirrel-2040系列数据记录器,用于在焊接过程中的热历史记录。热电偶点焊在板的顶面,分别位于不同距离焊缝中心线,在垂直于焊接方向和一半沿焊缝长度的线,如图18。
基于峰值温度的空间分布,焊缝形貌和尺寸可以预测。的纯激光焊接模拟横截面如图19。如果假定聚变边界对应于约1500°C的温度,那么它可以看出,预测的融合边界是大致平行的板的厚度方向,和焊缝的半宽度约为1毫米。计算出的焊缝几何尺寸和尺寸与实验结果吻合较好。
图20给出了在试样顶部表面点焊的热电偶的位置计算的热循环,并与实验结果进行了比较。每个位置的峰值温度都很好。预测的冷却速度也似乎是合理的在离焊缝中心线的距离为2.5毫米,虽然预测值与实测值之间的冷却速率大于3毫米的距离的差异。似乎有低估的趋势,冷却速度。然而,当预测焊接温度场图19与图5相比较,这有一个很好的相关性计算和试验焊缝形状。4讨论
4.1。冶金不同分带的微观组织转变
热分析的结果进行了验证,发现与实验结果吻合良好。由此产生的预测模型,可以用来推断的微观结构,有可能产生的激光焊接过程中。预测的热循环的位置,通过板的厚度的一半,但在不同的距离,从焊缝中心线,如图21所示。点从焊缝中心线下降0毫米和0.5毫米的距离,融合区内,而点在1毫米约恰逢融合线,并在1.5毫米的距离点有望在热影响区,而分在2毫米和2.5毫米的预期一致与ICHAZ和基材,分别。所预测的峰值温度在毫米,0.5毫米,1毫米,1.5毫米,2毫米和2.5毫米,2100毫米,1900°,1300°,°,920°,700°,°C,分别为0毫米、毫米和570°C。这些点的温度超过1500 C ~°有望熔合区内,而在2.5毫米的距离(母材)无固态相变的发生,因为在这个位置的峰值温度低于Ac1温度(700°C)。
根据连续冷却转变(CCT)508钢[ 23 ]图,为形成马氏体临界冷却速度为900°C/min(15°C/S)。根据模拟结果,在900和420°C(马氏体开始温度)之间的温度范围内的平均冷却速率,在0毫米,0.5毫米和1.5毫米的焊缝中心线的位置是675°c++,608°C和246°C /秒,分别。这些冷却速度比马氏体形成的临界冷却速度快得多。这意味着,熔合区和热影响区几乎肯定会转变为马氏体。根据仿真结果,从焊缝中心线的距离为2毫米,最高温度约为700°C(即AC1温度)。这一地区可能会接近ICHAZ的外边界。在距离焊缝中心线下2毫米,气温将高于700°C,但低于800°C(Ac3温度)。本区(ICHAZ)只能部分转变为奥氏体的焊接热循环过程中的。在随后的快速冷却过程中,任何新产生的奥氏体将被淬火形成马氏体。当马氏体转变停止,在这个温度仍会ICHAZ足够高的马氏体自回火。然而,其他未转化的材料(即材料不发生奥氏体化)将被保留,这可能采取的形式的过度回火铁氧体或贝氏体。在ICHAZ的最终组织将可能包括贝氏体和马氏体的混合了回火马氏体,如图7所示
(一)。
在焊缝中心线的距离为1.5毫米,峰值温度约为920°,根据模拟结果。的距离为1.5毫米,约1.8毫米之间的峰值温度将下降920°C和800°这区域对应FGHAZ之间。在FGHAZ峰值温度略高于Ac3温度(800°C)。材料是完全重新奥氏体化在这一地区,但有限的奥氏体晶粒生长由于相对较低的峰值温度和时间很短的时间在这个温度范围[ 28 ]和[ 46 ]。在下面的快速冷却过程中,这种细粒度的奥氏体转变为马氏体,在冷却过程中会有一定的马氏体。在FGHAZ最终组织将马氏体混合一些汽车回火马氏体。的微观结构和晶粒尺寸可以看到在图7(乙)组织在熔合区和热影响区的每个子带的GTA焊接接头几乎相同的激光焊接接头对应的子区域。然而,有更多的回火马氏体在每个子区域,由于较高的热输入和较慢的冷却速率与GTA焊接和激光焊接相比。4.2不同子带力学性能与微观结构的关系
MS(马氏体开始)SA508钢温度大约是420°C和马氏体的临界冷却速率约为15°C/S [ 23 ]。该钢的温度相对较高,马氏体形成的临界冷却速度相对较低。这可能导致GTA焊接熔合区和热影响区转变为马氏体。冷却速率在激光焊接熔合区和热影响区经历了比马氏体转变的临界冷却速度高出约20至40倍。这样的结果是所有的熔合区和热影响区向马氏体转变。具有高硬度马氏体是在激光焊接熔合区和热影响区的产生,以及在焊接条件下,激光的熔合区和热影响区的显微硬度焊缝超过一倍,相比于基体材料。这也发生在手动自体GTA焊接接头。这表明,508钢的情况下预热,GTA焊接在硬化焊接接头激光焊接具有相同的效果。如图7所示,从粗晶区各子区的显微组织变化(热)为细晶区(FGHAZ)然后一部分奥氏体化区(ICHAZ)随着距离的增加从熔合线。晶粒尺寸的变化,因为在不同的子带的不同的热循环。在焊接条件下,在粗晶区和细晶区变化在410 HV0.3的硬度,这是约的基础材料,双(200 HV0.3),而在ICHAZ的显微硬度明显低于~ 300 HV0.3。钢的强度和硬度之间有一个大致的比例关系,具有更高强度的材料,尽管这并不总是这种情况。熔合区的优势和热影响区各子区主要由马氏体碳化物沉淀在这些子区域和精细的改进。硬度测试结果表明,焊缝金属的屈服强度可以等于甚至超过的热影响区。在焊接热影响区的亚区的显微硬度分布与焊后热处理之前,在热影响区的亚区的屈服强度一致,如Lee等人的工作报告。[ 12 ]在SA508钢。他们表明,屈服强度超过1100兆帕的粗晶区和细晶区,也是基料约双屈服强度(500 MPa),而ICHAZ的屈服强度约600 MPa [ 12 ]。由于在ICHAZ材料只有部分转化为马氏体,在焊接过程中及其他未转化的材料保留,对ICHAZ的屈服强度低于粗晶区和细晶区的材料完全转变为马氏体。此外,由于较高的热输入和较慢的冷却速率与GTA焊接和激光焊接相比,更是自回火马氏体在冷却过程中,使硬度在GTA焊接接头熔合区和热影响区低于激光焊接接头。当然,我们必须牢记,SA508钢会一直进行焊后热处理焊后和大多数,如果不是所有的相变硬化,将逆转。不过值得建立在何种程度上的钢可能脆化的激光焊接工艺,和脆化的潜力一般会在焊接条件下最大。
与焊接过程中的硬化导致的焊接拉伸试验样品的基础材料,没有任何损失的强度。此外,窄熔合区是激光焊接的典型特征。这两个因素将有助于在激光焊接试样的夏比冲击试验的困难,即裂纹偏离焊缝为基料,从而误导冲击韧性的结果。一种激光焊接的夏比冲击试样失败具有较低的能量吸收值(66 J)进行测试时,在?40°这可能由于启动从缺口和偏离到基体材料中裂纹的发生,然后继续通过热影响区传播。此试样的裂纹路径可以在图14中看到。基体材料可以吸收一定的能量,但脆性区可以吸收较少的能量在骨折。另一个激光焊接试样失效具有更低的能量吸收值45,测试时在20?°这可能是由于启动从缺口裂纹并扩展直接通过热影响区。断裂路径(通过HAZ)此标本图14中可以看出(D)。脆性区不能吸收太多的能量在断裂之前。然而,还有其他两个激光焊接试样的断裂具有更高的吸收能量(约100 J)在?40°C和?20°C,分别。这可能是由于从缺口开始的裂缝,然后直接传播的基础材料。这些激光焊接试样的吸收的能量被发现要比那些在相应的测试温度下的基材料的更高。这可能归因于裂纹的弯曲的传播路径,从而增加了该地区的断裂面相比,从基底材料中提取的试样,从而增加了吸收的能量。曲线的旅行路径可以在图14中看到(乙)和(2)。所有的标本中提取的基础材料断裂的方式,与缺口对准,与一个相对直的路径,如图14所示。5结论
从这项工作中可以得出以下结论:(1)
激光焊接过程中产生的可接受的焊缝焊接6毫米厚的钢板508在较宽的范围内的焊接参数。焊缝无宏观缺陷。(2)
在焊接条件下,在一个6毫米厚钢板的激光焊接SA508机械性能类似于自体GTA焊接性能。焊缝拉伸试样断裂在母材远离焊接区。(3)
吸收能量的融合区的激光焊接被认为是比母材,基于子尺寸夏比冲击试样。(4)
为激光和GTA焊接试样在熔合区和热影响区的硬度,在焊接条件下,约为基体材料的双,为激光焊接稍高的测量值(~ 430 HV0.3)比GTA焊接(~ 410 HV0.3)。(5)
有限元模型的建立,在激光焊接过程中的冷却速率的情况下预热的20和40倍以上的马氏体形成的临界冷却速度。这表明,马氏体组织几乎总是在SA508钢作为激光焊接的后果。这些研究结果证实了实验工作,其中在激光熔合区和热影响区焊接焊接头的组织被发现包括马氏体混合一些自回火马氏体。(6)
而这些初步结果是令人鼓舞的,现在需要进一步的工作来评估在焊后热处理条件对SA508钢激光焊接性能,而且同样重要的是,这项工作扩展到评估在材料厚截面焊接接头激光性能。
参考文献
奥登《热冲压建模与仿真》(博士学位论文)吕勒奥理工大学(2006)
J.F.布雷迪,伦茨,美国所言,R.劳伦斯五《量身定制的性能,热成型的一个关键问题》 M.奥尔登堡,(主编),《第三届国际热金属片高性能钢形成诉讼》,卡塞尔(2011),页13–20施普林格出版社,柏林/海德堡/纽约(2002)贝谢,2003《钢–显微测定表观粒度》(2003)贝伦斯等,2012G.伯格曼,M.奥尔登堡
《由薄板淬火模拟热材料模型的验证热应力》(1997),页679–695 伯格曼和奥尔登堡,2004 《金属板材成形热机械分析的有限元模型》,59(2004),页1167–1186 ·乔治
《热点一个量身定制的性能–实验和建模实验室规模的B柱成形》 ·奥尔登堡(主编),《国际会议上的热金属片高性能钢》,奥尔巴赫(2011),页31–37 《有限元模拟DES》北德宝马集团,给姆比(主编),11。LS-DYNA论坛,乌尔姆,德国(2012),页84–86 M.默克莱因(主编),7。厄兰格车间埃朗根(2012),页133–151 《间接热冲压过程的相变动力学建模》 M.默克莱因,F.micari(主编),主题:钣金2013重要的工程材料,549卷(2013),页108–116瑞士
(博士学位论文)苏黎世联邦理工大学,苏黎世,瑞士(2012)侯德群,1938 A.侯德群
讨论“淬”冯射频研究物理。合金钢的淬透性(1938),页55–56施韦特费格,K.铁和铁碳合金的热力学性质:密度、热收缩 钢铁研究,62(1991),页24–33 《热冲压的回顾》J.S.柯卡尔迪,1997 《在低合金钢组织和淬透性预测》巴刻德斯坦(主编),对铁合金的相变国际会议(1983),页125–148 马尔堡,1959马伯格,R.E.《纯铁-碳合金和普通碳钢的奥氏体-马氏体相变的一般方程》金属学报,7(1959),页59–60 李等,2010 C.J.范泰恩
《端淬1045钢奥氏体分解动力学模型》工程,527(2010),页3186–3194 李等,1998 李红五,D.尼布尔,《一种钢的淬透性预测的计算模》1998),页661–672
第五篇:交通运输外文翻译外文文献
交通事故分析的可能性和局限性
S.Oppe 关键字:后果;目的;描述;限制;关注;事故分析;可能性
摘要:交通事故的统计数字,尤其国家一级的数据对监控和预测事故的发展,积极或消极检测事故的发展,以及对定义安全目标和评估工业安全特别有益。事故分析是应用非常有限的分析,是前瞻性分析和回顾性分析,能够对新开发的交通安全系统和特殊过程的安全措施进行评价。目前迫切需要一个将实时事故分析与研究相结合的行为。将自动检测和视频录制相结合的研究交通事故的科研论文会比较容易接受。这种类型的研究最终会对交通理念有个完善的认识。
1.简介
本文主要是基于个人的经验,研究有关交通安全、安全分析以及事故分析等在研究中的作用。由这些经验推导出的哲学思考就像通过研究和统计得出的实践观点。而这些调查数字已经在其他地方发表了。
在缺少直接观察的事故中,许多方法论问题的产生,导致不能直接测试对结果持续讨论。通过看事故视频来讨论是富有成效的。事实证明,用来解释事故的大部分有关信息就是事故中缺少的记录。深入研究还无法回忆起所有的必要的用来测试有关事故发生的假设数据。尤其是车-车相撞发生的车祸,这是在荷兰城市道路交叉口录制的视频,一辆从岔路驶来的汽车与主干路的汽车相撞,下列问题可以问:为什么汽车来自次干路上,突然加速后又几乎停止,撞上了在左侧主路的一辆汽车呢?为什么没有注意到正在驶来的车?是不是因为两车从右边驶来,司机因为前面的交叉为他们提供了可能性而斤斤计较?难道他向左看过,但他认为停在拐角处的绿色货车能让他停下来?当然,交通状况并不复杂。目前这个事故中没有骑自行车或行人在拥挤路口分散他的注意。如果停着的绿色车能够在五分钟内消失,这两辆车可能就不会相撞。在事故发生的相关条件下,几乎不可能观察下一个交通行为,因为交通事故是不可预见的。由于新的视频设备和自动检测事故设备的不断发展,如在收集数据方面不需要很高的成本就能变得越来越逼真。必要的增加数据类型也能更好的解释交通中存在的危险因素。关于事故分析的可能性和限制性的问题是不容易回答的,我们不能确切的分析交通事故。因为事故分析涵盖了每一个活动中的不同背景,并根据不同的信息来源范围来补充资料,特别是收集事故的数据,背景资料等,我们首先要看看在交通安全领域的活动周期然后再回答事故分析的可能性与限制。这些行为主要是与交通系统的安全管理有关,有些则是相关的研究活动。
应该用下面的步骤来加以区分: ——检测交通安全问题;
——描述问题和它的主要特征; ——分析其原因分析和改进建议; ——选择和执行安全措施; ——评价所采取的措施。
虽然这个周期可以由同一人或一群人做出来,而问题在每个阶段(政治/管理或科学)都有不同的背景。我们用事故分析来描述这一阶段。做这个决定是重要的。很多关于分析结果的方法的讨论由于忽视之间的区别而成为徒劳的。政治家或道路管理人员对道路的个别事故不是很留意。他们对事故的看法往往都是一视同仁,因为总的结果比整个事故中的每个人的因素重要。因此,每次事故看做一个个体,之间相互协调就会达成安全的结果。
研究人员研究事故发生时一连串事件中每个人的兴趣。希望从中得到关于每次事故的详细信息并能发现其发生的原因和有关的条件。政治家们希望只是因为细节决定行动。在最高一级事故总数减少。信息的主要来源是国家数据库及其统计学处理系统。对他来说,统计意外数字及其统计的波动来进行事故分析。这适用于事故分析中的交通安全领域。因此,我们将首先描述了事故的这些方面。2.事故的性质和它们的统计特性
事故基本概念是意外,不管是其发生的原因还是引起事故出现的过程。两个简单的假设通常是来描述交通事故的形成过程:
-事故发生的概率与以往发生的事故之间是独立;-事故发生在时间上是同性质的
如果这两个假设成立,那么事故是泊松分布。第一个假设与大多数的批判不符。事故是罕见的事件,因此不会受到以前事故的影响。在某些情况下,有一个直接的因果链(例如,大量的车开到一起)这一系列的事故被认为是一个个体事故但包含许多的车。这个假设并不适用于统计人员伤亡。伤亡人数往往与同一事故有关,因此,独立性假设不成立。第二个假设乍一看似乎不太容易理解。穿越空间或在不同地点发生的的事故同样具有可能性。然而,假设需要很长一段时间并且没有缓缴期。其性质是根据理论的假设。如果其短时间内能成立,那么它也适用于长时间,因为泊松分布变量的总和,即使他们的泊松率是不同的,但也属于泊松分布。对于这些时期的总和泊松率则等于为这些地方的泊松率的总和。假设与一个真正的情况相比较计数,无论是从一两个结果还是总情况来看都有一个基本情况比较符合。
例如,对比在一年中特定的一天例如下一天,下一个星期的一天发生的交通事故。如果条件是相同的(同一时间,交通情况相同,同样的天气条件等),那么由此产生的意外数字是相同的泊松过程的结果。这一假设可以通过估算进行测试的两个观测值的基础上(估计是两个值的平均值)的速度参数。概率理论能够
考虑到这两个观察值的平均,用于计算的平等假设的可能性。这是一个相当强大的统计过程。泊松假设是研究了很多次,来获得证据支持。它已经应用于许多情况,数的差异表明在安全性的差异然后确定是否发生意外。这一程序的主要目的是检测在安全分歧。这可能是一个时间上的差异,或不同的地方或不同的条件。这种差异可以指导改进的过程。由于主要关注的是,以减少意外的发生,这种分析可能导致对治疗中最有前途的领域。为这样一个测试应用程序的必要条件是,那意外的数字进行比较是大到足以证明存在的分歧。在许多地方情况下,一个应用程序是不可能的。事故黑点分析往往阻碍了这一限制,例如,如果应用这种测试,找出事故是否在特定的位置数是高于平均水平。该程序的描述,也可以使用,如果发生意外乃根据数的特点找到有前途的安全目标。不仅聚集,而且还与分类泊松假设成立,而意外数字可以相互测试的泊松假设的基础。这种测试是相当麻烦的,因为每个特定的情况下,每一个不同的泊松参数,即,对所有可能结果的概率必须计算应用测试。然后,泊松分布近似为正态分布,均值和方差等于泊松参数。一旦均值和方差的正态分布,给出了所有的测试可以改写了标准零均值和
方差的正态分布条件。没有任何更多的必要计算,但测试统计,需要利用表绘制。3.行车安全政策事故统计的应用
分析那些假设的基础上描述的测试程序的类型及其优点。这种应用最好的例子是为一个国家或地区进行超过一年的安全监测,用事故的总体数据(最终的特定类型,如死亡事故)与前几年的数据相比较。根据数年的事故序列,能够分析出它的发展趋势,并大致预测以后几年的事故数量。一旦建立了这样一种趋势,那么在误差范围内未来一年或几年都可以预见。从一个给定趋势的偏差也可以进行预测新的事件。最有名的是斯米德在1949年进行的分析。我们将讨论这个事故类型分析更详细的内容。
1、该测试应用推广到高阶分类。Foldvary和Lane(1974),在衡量强制佩戴安全带的效果,谁是最早应用于值的4路表高阶相互作用的总卡方分配的。
2、测试不局限于总体影响,但卡方值就可以分解模型内子假说。另外,在双向表,卡方总可以分解成零件表互动的作用。对1的优势。和2。比以前的情况是,这对许多相互关联的(子)表和相应的智广场卡方检验是由大量分析,取而代之的是一个一卡方的确切划分。
3、投入更多关注的是参数估计。例如,在卡方分割使人们有可能以测试有关行参数的线性或二次限制或趋势的不连续性。
4、分析的单位是从数到广义加权计数。这对于道路安全分析,那里一段时间,道路使用者的数量,地点或公里数的车辆往往是必要的修正有利。最后一个选项是没有发现在许多统计软件包。安徒生1977年给出了一个用于道路双向安全分析表的例子。工资保障运动的一个计算机程序。这一级没有说明事故原因分
析。它会尝试检测安全问题需要特别注意。所需的基本信息包括事故数字,来形容不安全总额,暴露的数据来计算风险,并找到一个高风险的情况下或(团体)道路使用者。
4.事故分析研究目的
交通安全的研究是有关的事故及其后果的发生。因此,人们可能会说,研究对象是意外。然而研究人员的兴趣较少集中在这个最后的结果本身,而是多在进程更多的结果(或不结果)的事故。因此,最好是把作为他的研究对象,在流量的重要事件。一个在交通意外的过程,结果是,该实际发生是由研究者未落观测研究的主要问题。
调查一宗交通意外,他将努力重建了间接来源的事件,如涉及的道路使用者,所提供的资料或目击者有关情况,车辆,道路和司机的特点。因此这不是科学独特的,也有一个间接的研究对象的研究更多的例子。但是,第二个困难是,该研究的对象不能被诱发。有系统的控制实验手段研究只对问题方面的可能,而不是问题本身。
间接观察和缺乏系统的控制组合使调查人员很难发现在什么情况下造成事故的因素。虽然研究人员主要是在事故处理领导有兴趣,他几乎完全信息的后果,它的产品,意外。此外,事故背景是复杂的。一般来说,可分为以下几个方面:
-考虑到交通系统,交通量和组成国家,道路使用者,他们的速度,天气条件下,路面情况,车辆,道路使用者和他们的相互作用的演习,意外可以或无法预防。
-由于发生事故,也对这样的速度和车辆质量的因素,大量的不同,碰撞角度,对道路使用者和他们的脆弱性,影响等位置的保护,伤害是严重或或多或少物质损失是多还是少可观。虽然这些方面不能独立研究从理论的角度看,它也从由此产生的结果的优势,区分交通情况有潜在危险的数字,是由有一个意外的可能性,在这种潜在的危险局势,给定一个特定事故。
这个概念框架是对风险的关于个别道路使用者,以及上级的决定控制器的决定制定的一般基础。在风险的数学公式,我们需要一个明确的概率空间的介绍,基本事件(的情况),可能导致事故组成,每个类型的事件的概率,最终收在一次事故中,最后的具体成果,损失,鉴于事故的类型。
另一种方法是看事故特征组合,然后找出关键因素。这种类型的事故分析是通过分析事故的共组或子群来开展。事故本身是一个研究的单位,但也要研究道路因素:道路位置,道路设计(如一个弯道)等。
原文出处:SWOV institute for road safety research Leidschendam(会议记录),记录者,S.Oppe.POSSIBILITIES AND LIMITATIONS OF ACCIDENT
ANALYSIS
S.Oppe Keyword:Consequences;purposes;describe;Limitations;concerned;Accident Analysis;possibilities Abstraet:Accident statistics, especially collected at a national level are particularly useful for the description, monitoring and prognosis of accident developments, the detection of positive and negative safety developments, the definition of safety targets and the(product)evaluation of long term and large scale safety measures.The application of accident analysis is strongly limited for problem analysis, prospective and retrospective safety analysis on newly developed traffic systems or safety measures, as well as for(process)evaluation of special short term and small scale safety measures.There is an urgent need for the analysis of accidents in real time, in combination with background behavioural research.Automatic incident detection, combined with video recording of accidents may soon result in financially acceptable research.This type of research may eventually lead to a better understanding of the concept of risk in traffic and to well-established theories.1.Introduction.This paper is primarily based on personal experience concerning traffic safety, safety research and the role of accidents analysis in this research.These experiences resulted in rather philosophical opinions as well as more practical viewpoints on research methodology and statistical analysis.A number of these findings are published already elsewhere.From this lack of direct observation of accidents, a number of methodological problems arise, leading to continuous discussions about the interpretation of findings that cannot be tested directly.For a fruitful discussion of these methodological problems it is very informative to look at a real accident on video.It then turns out that most of the relevant information used to explain the accident will be missing in the accident record.In-depth studies also cannot recollect all the data that is necessary in order to test hypotheses about the occurrence of the accident.For a particular car-car accident, that was recorded on video at an urban intersection in the Netherlands, between a car coming from a minor road, colliding with a car on the major road, the following questions could be asked:Why did the driver of the car coming from the minor road, suddenly accelerate after coming almost to a stop and hit the side of the car from the left at the main road? Why was the approaching car not noticed? Was it because the driver was preoccupied with the two cars coming from the right and the gap before them that offered him the possibility to cross? Did he look left before, but was his view possibly blocked by the green van parked at the corner? Certainly the traffic situation was not complicated.At the moment of the accident there were no 5
bicyclists or pedestrians present to distract his attention at the regularly overcrowded intersection.The parked green van disappeared within five minutes, the two other cars that may have been important left without a trace.It is hardly possible to observe traffic behaviour under the most relevant condition of an accident occurring, because accidents are very rare events, given the large number of trips.Given the new video equipment and the recent developments in automatic incident and accident detection, it becomes more and more realistic to collect such data at not too high costs.Additional to this type of data that is most essential for a good understanding of the risk increasing factors in traffic, it also important to look at normal traffic behaviour as a reference base.The question about the possibilities and limitations of accident analysis is not lightly answered.We cannot speak unambiguously about accident analysis.Accident analysis covers a whole range of activities, each originating from a different background and based on different sources of information: national data banks, additional information from other sources, specially collected accident data, behavioural background data etc.To answer the question about the possibilities and limitations, we first have to look at the cycle of activities in the area of traffic safety.Some of these activities are mainly concerned with the safety management of the traffic system, some others are primarily research activities.The following steps should be distinguished:description of the problem and its main characteristics;selection and implementation of safety measures;the probability of an accident to occur is independent from the occurrence of previous accidents;-the occurrence of accidents is homogeneous in time.If these two assumptions hold, then accidents are Poisson distributed.The first assumption does not meet much criticism.Accidents are rare events and therefore not easily influenced by previous accidents.In some cases where there is a direct causal chain(e.g., when a number of cars run into each other)the series of accidents may be regarded as one complicated accident with many cars involved.The assumption does not apply to casualties.Casualties are often related to the same accident and therefore the independency assumption does not hold.The second assumption seems less obvious at first sight.The occurrence of accidents through time or on different locations are not equally likely.However, the assumption need not hold over long time periods.It is a rather theoretical assumption in its nature.If it holds for short periods of time, then it also holds for long periods, because the sum of Poisson distributed variables, even if their Poisson rates are different, is also Poisson distributed.The Poisson rate for the sum of these periods is then equal to the sum of the Poisson rates for these parts.The assumption that really counts for a comparison of(composite)situations, is whether two outcomes from an aggregation of situations in time and/or space, have a comparable mix of basic situations.E.g., the comparison of the number of accidents on one particular day of the year, as compared to another day(the next day, or the same day of the next week etc.).If the conditions are assumed to be the same(same duration, same mix of traffic and situations, same weather conditions etc.)then the resulting numbers of accidents are the outcomes of the same Poisson process.This assumption can be tested by estimating the rate parameter on the basis of the two observed values(the estimate being the average of the two values).Probability theory can be used to compute the likelihood of the equality assumption, given the two observations and their mean.This statistical procedure is rather powerful.The Poisson assumption is investigated many times and turns out to be supported by a vast body of empirical evidence.It has been applied in numerous situations to find out whether differences in observed numbers of accidents suggest real differences in safety.The main purpose of this procedure is to detect differences in safety.This may be a difference over time, or between different places or between different conditions.Such differences may guide the process of improvement.Because the main concern is to reduce the 7
number of accidents, such an analysis may lead to the most promising areas for treatment.A necessary condition for the application of such a test is, that the numbers of accidents to be compared are large enough to show existing differences.In many local cases an application is not possible.Accident black-spot analysis is often hindered by this limitation, e.g., if such a test is applied to find out whether the number of accidents at a particular location is higher than average.The procedure described can also be used if the accidents are classified according to a number of characteristics to find promising safety targets.Not only with aggregation, but also with disaggregation the Poisson assumption holds, and the accident numbers can be tested against each other on the basis of the Poisson assumptions.Such a test is rather cumbersome, because for each particular case, i.e.for each different Poisson parameter, the probabilities for all possible outcomes must be computed to apply the test.In practice, this is not necessary when the numbers are large.Then the Poisson distribution can be approximated by a Normal distribution, with mean and variance equal to the Poisson parameter.Once the mean value and the variance of a Normal distribution are given, all tests can be rephrased in terms of the standard Normal distribution with zero mean and variance one.No computations are necessary any more, but test statistics can be drawn from tables.3.The use of accident statistics for traffic safety policy.The testing procedure described has its merits for those types of analysis that are based on the assumptions mentioned.The best example of such an application is the monitoring of safety for a country or region over a year, using the total number of accidents(eventually of a particular type, such as fatal accidents), in order to compare this number with the outcome of the year before.If sequences of accidents are given over several years, then trends in the developments can be detected and accident numbers predicted for following years.Once such a trend is established, then the value for the next year or years can be predicted, together with its error bounds.Deviations from a given trend can also be tested afterwards, and new actions planned.The most famous one is carried out by Smeed 1949.We will discuss this type of accident analysis in more detail later.1.The application of the Chi-square test for interaction is generalised to higher order classifications.Foldvary and Lane(1974), in measuring the effect of compulsory wearing of seat belts, were among the first who applied the partitioning of the total Chi-square in values for the higher order interactions of four-way tables.2.Tests are not restricted to overall effects, but Chi-square values can be decomposed regarding sub-hypotheses within the model.Also in the two-way table, the total Chisquare can be decomposed into interaction effects of part tables.The advantage of 1.and 2.over previous situations is, that large numbers of Chi-square tests on many interrelated(sub)tables and
corresponding Chi-squares were replaced by one analysis with an exact portioning of one Chi-square.3.More attention is put to parameter estimation.E.g., the partitioning of the Chi-square made it possible to test for linear or quadratic restraints on the row-parameters or for discontinuities in trends.4.The unit of analysis is generalised from counts to weighted counts.This is especially advantageous for road safety analyses, where corrections for period of time, number of road users, number of locations or number of vehicle kilometres is often necessary.The last option is not found in many statistical packages.Andersen 1977 gives an example for road safety analysis in a two-way table.A computer programme WPM, developed for this type of analysis of multi-way tables, is available at SWOV(see: De Leeuw and Oppe 1976).The accident analysis at this level is not explanatory.It tries to detect safety problems that need special attention.The basic information needed consists of accident numbers, to describe the total amount of unsafety, and exposure data to calculate risks and to find situations or(groups of)road users with a high level of risk.4.Accident analysis for research purposes.Traffic safety research is concerned with the occurrence of accidents and their consequences.Therefore, one might say that the object of research is the accident.The researchers interest however is less focused at this final outcome itself, but much more at the process that results(or does not result)in accidents.Therefore, it is better to regard the critical event in traffic as his object of study.One of the major problems in the study of the traffic process that results in accidents is, that the actual occurrence is hardly ever observed by the researcher.Investigating a traffic accident, he will try to reconstruct the event from indirect sources such as the information given by the road users involved, or by eye-witnesses, about the circumstances, the characteristics of the vehicles, the road and the drivers.As such this is not unique in science, there are more examples of an indirect study of the object of research.However, a second difficulty is, that the object of research cannot be evoked.Systematic research by means of controlled experiments is only possible for aspects of the problem, not for the problem itself.The combination of indirect observation and lack of systematic control make it very difficult for the investigator to detect which factors, under what circumstances cause an accident.Although the researcher is primarily interested in the process leading to accidents, he has almost exclusively information about the consequences, the product of it, the accident.Furthermore, the context of accidents is complicated.Generally speaking, the following aspects can be distinguished: Given an accident, also depending on a large number of factors, such as the speed and mass of vehicles, the collision angle, the protection of road users and their vulnerability, the location of impact etc., injuries are more or less severe or the material damage is more or less substantial.Although these aspects cannot be studied independently, from a theoretical point of view it has advantages to distinguish the number of situations in traffic that are potentially dangerous, from the probability of having an accident given such a potentially dangerous situation and also from the resulting outcome, given a particular accident.This conceptual framework is the general basis for the formulation of risk regarding the decisions of individual road users as well as the decisions of controllers at higher levels.In the mathematical formulation of risk we need an explicit description of our probability space, consisting of the elementary events(the situations)that may result in accidents, the probability for each type of event to end up in an accident, and finally the particular outcome, the loss, given that type of accident.A different approach is to look at combinations of accident characteristics, to find critical factors.This type of analysis may be carried out at the total group of accidents or at subgroups.The accident itself may be the unit of research, but also a road, a road location, a road design(e.g.a roundabout)etc.