大学英文课堂演讲稿 (混凝土材料的无损测试)[合集五篇]

第一篇：大学英文课堂演讲稿 (混凝土材料的无损测试)

Presentation draft of teaching Non-destructive evaluation for FRP-bonded concrete structures

Good afternoon, I am honored and pleased to be here to give you a lecture.Today I will introduce to the nondestructive evaluation for the FRP-bonded concrete structures.Before I start, let me introduce myself.My name is XXX, I am from the department of Architecture and Civil engineering.Now let me show you the intended learning outcomes.By the end of this session, I hope you can achieve the following learning goals.The first learning goal is to understand the history of the FRP-bonded concrete structure.The second learning goal is to understand what causes the defects in the FRP-bonded concrete structures and why should we inspect these defects.The third learning goal is to understand the principles, advantages and disadvantages of the current non-destructive methods for inspection of FRP-bonded concrete structures.This course is designed to help you learn more about the applications the FRP materials in the civil infrastructures and know more about the current problems and issues of the FRP-bonded concrete structures.Students will understand the principles, advantages and disadvantages of the non-destructive evaluations for condition assessment of the FRP-bonded concrete structures.Concrete structure is one of the most widely used modern building styles in the world.The use of the concrete

thmaterials has become very popular since the invention of the Portland cement in 19 century.However, a large number of the existing concrete structures are becoming older and older.Many of the concrete structures in the world age beyond 50 years and they are suffering from the significant deterioration and distress.Therefore, it is required to repair or retrofit the old concrete structures.The conventional way to retrofit or repair the concrete structure is to insert the steel bar or attach the external steel plate to the concrete substrate.However, strengthening the concrete structure with the steel materials has some fatal disadvantages.For example, the steel bar or steel plate is very heavy and bulky, that is to say, the strength to weight ratio is very low for the steel reinforcement.Another limitation is that it is difficult to fix or install the steel reinforcement to the concrete structures.The last but not the least drawback is that the steel materials are susceptible to the corrosion or environmental degradation.In view of the factors, there is a need to look for alternatives to strengthen the concrete structures.An excellent solution to combat the disadvantages of the steel reinforcement is the use of FRP materials.FRP is abbreviation of the fiber reinforced polymer.It is a widely used composite material in various industries, such as aerospace, the mechanical industry and the construction.The FRP materials have a series of the advantages as compared to the steel materials.For example, the high strength to weight ratio;the excellent resistance to the corrosion and the environmental degradation;flexible and easy to form different kinds of the shapes.You can find other advantages of the FRP materials in these references.In terms of the FRP strengthening, the common practice is to bond the FRP sheet to the concrete substrate.The bonding materials is usually the adhesive materials such as the epoxy.However, in practice, the defects are always existing in the FRP-bonded concrete structures.Several reasons can be explained for the defects.The first one is the external loading conditions.If the FRP-bonded concrete material is subjected to the large loading forces which is beyond its loading capacity, the cracks inside the concrete or the FRP delamination can occur.The second one is the perfunctory manufacturing.Due to the poor workmanship during the fabrication of the materials, the defects can be induced.The third one is that environmental degradation.Since that most of the FRP-bonded concrete structures are exposed to the air or marine environment, the materials are suffering from the corrosion such as the carbonation, moisture attack and so on.The bonding quality of the FRP-concrete can be weakened due to these environmental effects.Such defects are often in the form of cracks, air bubbles trapped under the FRP sheet or FRP delamination.The three pictures show the different kinds of the defects in FRP-bonded concrete structures.If we don’t inspect these defects, the performance of the FRP-bonded concrete will be weakened gradually and finally poses a threat to the safety of the building.Now I am going to introduce the defect inspection in FRP-bonded concrete structures.Since these defects are often covered up by the FRP sheet, the visual inspection by the naked eyes may be impossible.Even though tapping with a hammer and listening to the sound may help identify the presence of the defect, it cannot quantify the extent of the defects.So in this case, it is crucially important to find out an effective way to inspect the FRP-bonded concrete structure.Non-destructive evaluation can be an effective way to address this issue.The following slides will present the commonly used NDE methods.And I will let you understand the principles, advantages and disadvantages of each NDE methods.Acoustic emission.Acoustic emission has been applied for the condition assessment of the materials and structures for about six decades.The method is based on recording and describing the acoustic waves emitted from a rapid release stress energy within a tested object which is under the mechanical forces.Proper analysis of these acoustic signals can provide information concerning the location of discontinuities.The advantages of the method is that damage process in materials being tested can be observed during the entire loading history.The disadvantages of the method is that it requires the physical contact between the AE sensor and the concrete structure through the use of the sound coupling.This is inconvenient to detect the areas where it is not easy to access.For example, it is difficult or even dangerous for the field inspector to climb up the bridge or overpass to perform the test.Infrared thermography is a non-contact method which can be carried out at a certain distance from the tested object.The technique measure the surface temperature of an object by detecting the amount of energy emitted by the target in the infrared band.Look at these pictures, the brighter areas in the infrared image typically signify the higher temperature regions while darker areas indicate the lower temperatures.Based on the phenomenon, infrared thermography measures and images the differential temperatures of a structure so that the defect can be recognized.The advantages of the method is that it is non-contact, which means it can be tested at a certain distance from the object.The disadvantages of the method is that for large scale structural inspections, a relatively expensive scanner and other devices are required.Another limitation of the method is that special precaution needs to be taken to avoid interference that come from the varying ambient temperature conditions.Next, I will introduce you the radiography method.Radiography method involves in using the short wavelength electromagnetic radiations(e.g.X-rays)which can be absorbed by the materials as it penetrates the objects.The amount of the absorption is determined by the density of the materials.The advantages of the method is that it has a long history and it is a mature method.The technique has been used in industrial applications for more than 50 years as well as more than 30 countries.The disadvantages of the method is that threat towards the health of whom conducts the test due to the long exposure of radiation.Acoustic-laser technique has a potential to be a powerful tool for the inspection of FRP-bonded concrete.This technique is based upon the acoustic excitation on the surface of interested region and the measurement of its vibration using laser beam.In this study, a photoreceiver is used in the technique system to receive and record the optical signals sent by the laser beam.Acoustic-laser technique has a series of advantages as below: remote inspection due to the high concentration of the laser beam;capacity to detect the small structural elements since the beam size of the laser is small;low maintenance and low operating costs;light weight and mobility.The disadvantages of the method is that the main drawback of the technology is that the sensitivity diminishes with an increase with the defect depth measured from the object surface.Before the end of this class, I should inform you that you have to do the assignment task after this class.The assignment makes up 50% credits and please remember the deadline of subsuming to your work.The assignment is to write a review paper.The tittle is given to you: Review on the state-of-art NDE methods for assessment of FRP-bonded concrete structure.You will also have to make a presentation based on your paper in the class.When you submit your homework, please hand in the hard copy as well as the PPT slides print out.I am looking forward to see your presentation.So that is the end of the class if no questions to ask me.Do you have any questions or comments about my lecture, please hand up your hand and I would like to give you the answers.Thank you.

第二篇：大学英文演讲稿

导语：也许你爱演讲却并不是一个能言善道的人，也许因为这点，你就失去了走上演讲台的勇气。其实，有时候如果你有一篇好的演讲稿，那么你就已经成功了一半。下面是小编给大家分享的大学英文演讲稿模板，仅供参考。

大学英文演讲稿模板一

I have been in college for about one year.During my stay here, I came to realize that college life is like drinking coke.We experience all tastes of life here, sour, sweet, bitter and hot.I am from Province, which is far away from here.I often miss my Mum, friends, and relatives in my hometown.However, I can't see them very often.So loneliness always keeps me company.I am sad that I can't be there with them.Lucky for me, life in college is rich and colorful.With more free time,we can do many more things besides study, such as joining societies clubs, and taking part-time jobs.Such activities not only make our life more colorful, but also help us improve all kinds of skills.The college is a society miniature, what we learn here will benefit our future life.Our path in life will not always be smooth.Setbacks can't be avoided.Failing an important exam, break up with boy or girl friend, or refused by a promising company, such setbacks are likely to get us down.Sometimes we fell so frustrated that we even burst into tears.Drinkin coke is wonderful, despite the undesirble consequent hiccups.It's bitter, sour and peppery, but also sweet.And you'll even feel excited after gulping down a glass.A college experience is part of growing up.We cry, smile, fall in love, get hurt, leave, learn and then we become a better person.college life is like drinking coke.I'm experiencing it.And I know, I enjoy it!

大学英文演讲稿模板二

good morning everyone.my name is ***.today my topic is my college life.i wish i could share my happiness and annoyance i have experienced with you all.tuo years ago i came into the city of qinhuangdao and started my college life in e&a college, the most memorable journey of my life.i was just a shy and little boy that time.all the things seemed fresh to me: new faces, military training, large library and physics lab etc.i breathed the air of college greedily, but to tell the truth, the air in qinhuangdao is wonderful.it’s really hard to explain my feelings that time: curiousenergeticin one word, i was really happy that time.and now i am going to be a junior in july.recalling to the two years, i think i have to talk about one thing-----learning.learn how to study independently, learn how to get along with others, learn to love, learn tooh, there are too much things we have to learn.that’s my college life.i cherish all i have experienced in college.i love you, my college!

that’s all, thank you！

大学英文演讲稿模板三

my college, my dream!

respect teacher, dear students, everybody!i came from the higher vocational college, mechanical class liupengbo!today, the topic of my speech is my college, my dream!.septembercarrying suitcases full of my college.remember that day, the building in front of the set with each department of tent, the tent is full of all sorts of color series clothing learn elder sister of the seniors.stadiums filled with chase dreams of college students, like me full.and i saw the tents in our department.remember that day, i quietly in the cut warm greetings from seniors who have spent time...as if the blink, but before we look back, it has quietly between our fingers across.in college, some people really have a very full, very happy, they think deeply miss this is a cant repeat the pure land of the rest of my life.also some people, from a step into the campus, and i was very disappointed, feel everything is not the same as you think, muddle along from then on, until eventually wake up suddenly found that, as if overnight, the college has in the past, so also lost their precious youth.however, only regret college

mix for a couple of years, but there wont be regret in the college.in school, even the fall of his alma mater, is like hell on earth, who over the years, college of memories, also often with emotion, even tears.no matter how much you have a college, at least you should always remind yourself: life is only one college stage.flower of life is the spring of life, it is beautiful, but short-lived.as a college student should, during this period to study hard, strive forward, to find a belongs to own sky.as a college student of the 21st century, we must have his own dream, like the night sky must have the stars, the earth has a life, this college will be fruitful, so that youth is energized, so that life is dynamic, so that life is full of victory, is full of joy.youth, beat forever is in the eyes of the era.dream, in the dictionary of youth is an eternal belief.and college in the world of dreams always is so beautiful, so holy!

my college, my dream, youth dance, the wind with the rain together.大学英文演讲稿模板四

hello everyone!my name is king, a student from college.i am glad to give you a speech about my college.the title of my speech is my college, my home.last september i left my hometown with heavy baggage and after a journey of ten hours, i came to this dream campus with great expectation and excitement.whenever i recall the past days, so many thoughts are flooding in my mind.but what impressed me most is a night when i got a stomachache during the first days.i had to turn to the aunts in charge of our dormitory for help.they were so friendly and warm-hearted.they gave me the pills and reminded me of having more hot water.i recovered soon and i thanked them from the bottom of my heart because they brought me the warmth of home.our college is a famous academic center.the teaching staff are all learned professors.many of them are world-wide known for their wide range of knowledge and charming personality.i respect my teachers!i admire my teachers!i love my teachers!various activities are carried here.they not only bring me happiness but also improve myself.i meet with a lot of classmates and make a large number of friends.when i feel upset, the will give me a hand;when i am happy, i will share with them.the library has a large collection of books and i always lose myself in it.i believe they will benefit me a lot and are to broaden the roads of my future.i love you,****college!you are just a place which gives me warmth and strengths!you are my home!

大学英文演讲稿模板五

good morning everyone.my name is zhang san.today my topic is my college life.i wish i could share my happiness and annoyance i have experienced with you all.four years ago i came into the city of baoding and started my college life in ncepu, the most memorable journey of my life.i was just a shy and little boy that time.all the things seemed fresh to me: new faces, military training, large library and physics lab etc.i breathed the air of college greedily, but to tell the truth, the air in baoding is terrible.it’s really hard to explain my feelings that time: curiousenergeticin one word, i was really happy that time.and now i am going to graduate in july.recalling to the four years, i think i have to talk about one thing-----learning.learn how to study independently, learn how to get along with others, learn to love, learn tooh, there are too much things we have to learn.another relationship in college is friendship.my roommates have lived four years with me.in these years, they forgive my faults, cry with me, laugh with me, play with methey always stand with me and support me, i have learned a lot from them.i love them all and treasure the friendship with them.that’s my college life.i cherish all i have experienced in college.i love you, my college!that’s all, thank you!

第三篇：英文课堂五分钟演讲稿

The two years in College of International Culture and Education

Today I’m standing here,willing to share my story in College of International Culture and Education.These two years will become the most precious memory baried deeply in my mind.If you ask me what’s the most impressive thing that happened in these two years,I might be blind-minded.But when I think over,all the details in daily life will make me wanna smile.I can’t remember the feeling when I step in this familiar school for register.I have never imagine I will go to this university for further education.I have live and grown up in this place.I have no expect that I will have a good time in here.But the reality can always surprise me although this is not what I want at the beginning,I received a lot in the end.In these two years,I’ve made amazing friends who will always stand by my side,give me strength to conquer all the difficulties,comfort me when I am upset and doubt the love around me.They make me strong,full of confident,trust people at the same time,earned trust from them.Their existence truly makes a more beautiful world,and make me believe that we can still have something that is free to get and no need to return.In these two years,I held the post of monitor for one semester,I was very glad that I can lead the whole class and earned respect and acception,all the classmates were willing to help me with my work.We acomplished a lot of tasks perfectly.your support make me valuable,more talented,have faith to continue serving the class.make better class reputation,let everyone knows that our team is much more strong than you think.We held an interesting sports meeting that I will never forget.How inspiring to see that everyone is doing whatever they can to complete a teamwork.Wewander what kind of game people can have fun,meanwhile it can make some sense in life.We prepared meterials,borrow equipments from other departments,we even rehearse an opening dance for entertaining.We told ourselves this is our time,and now,just like old times,we get together,ready to give a talent show,it’s not just a show to prove ourself,we know how good we are,it’s also a gift to College of International Culture and Education,it company us for two years,be our stage and exhibit the culture diversity in front of our eyes.I should memorize the days in this college,it will support me at least two years when I’m not able to see these familiar face anymore.How much will I miss you guys,but now it’s time to say good bye.

第四篇：大学校园生活英文演讲稿

大学校园生活英文演讲稿、Friendship is indispensable to people's life.A man without friends is an angel without wings, whose life will suffer in the long tolerance of loneliness and depression.Friendship is the mother of our psyche, who'll warm her kid when hurt occurs.We have much to share with our friends in life, perplexity, excitement, bitterness etc.Alas, it's magnificent to maintain a genuine friendship.It takes many special qualities to make a friend.Understanding should come first.Only when we get a better understanding of each other can we gain an authentic and meaningful friendship.We may find our hobbies of common interests.This feeling of affinity gets us closer and closer.It also takes a special kind of love that seems to know no end.Never hesitate to show your heartfelt care and kindness to your friend when he/she is in trouble.Love is not selfish.Love is endowed by God that we should treasure all our life.Tolerance is the third essential part in friendship.We are absolutely different persons.This individual distinction may cause conflict between us in every aspect of our life.Don't immerse ourself in this infliction too long.Try to tolerant his/her in an introspective mood.Saints are not perfect, let alone those ordinary people like us.Afterwards, we should get a good communication.Never shy to confess.Understanding, love and tolerance are the first three essences that comes to an authentic friendship.Other qualities are also concerned such as thoughtfulness, trust and patience.Remember, friendship is your psyche's guard, treasure it

第五篇：3分钟大学课堂演讲稿

失败得越多越早,成功就越快来临

大三的时候，身边的很多朋友包括我自己，不时地感到心情浮躁，未来前景迷茫，学的时候不用心学，玩的时候又感到慌张、负罪。

转眼大四了，大家忙于考研、考公、找工作，看上去是没时间迷茫了，打心底里仔细问问自己，害怕失败吗？如果失败了，我下一步怎么办？

你看过这样的毒鸡汤吗，“寒冬酷暑，披星戴月，自习室从一楼到四楼九十六级台阶，我背着沉甸甸的梦想，走过了三百多个日夜……”，“人生的路有起有落，只不过现在低谷，未来是明路”。我今天的演讲主题很老套，跟上述的毒鸡汤并没有什么本质区别，“失败与成功”，失败乃成功之母，题目来源于著名的设计公司IDEO现任的首席执行官蒂姆〃布朗说过的一句话：“失败得越多越早，成功就越快来临。”

再次询问下自己，“我为什么想要成功？”答案是，考研成功了学历更高，工作仿佛更好找，工资水准仿佛更高，又或者，我现在很迷茫，为了逃避找工作因此想继续升学，再或者我找到了更感兴趣的专业，我是为了梦想。有很多很多的答案，它们有个共性，那就是，我觉得，我认为，考上了，与我的现状相比，更美好。那为什么担心失败呢？因为我害怕，付出了精力没有回报，害怕落榜了还要去找工作，等等。

回到IDEO的这句话来，IDEO为了开拓它的员工的头脑，收纳更多的创新点子，传递了这条理念。同时，为了他的员工不害怕失败，对失败的设计产品给予了不亚于最终设计成功所获得的回报。他提倡有效率的失败，失败的越快越多，反过来讲，就是越快诞生出相比较上一次失败更有所进步的点子，在这个过程中员工所收获的经验甚至思维训练，比一次偶然的巧合的成功要多得多。从它的这条理念看，最后的结果不再重要，大家追随的不再是结果成功与否，而是我怎么改进现在的产品，让它比上次更好。

放到考研上、考公上来讲，我们这场旅程无疑是漫长的、艰苦的，让人觉得仿佛回到了高三，你觉得高三精彩吗、难忘吗？那么为什么还要在意最后的结果呢，不管怎样，人生的路像是河流，一直在流淌而不停滞，20年后，你大概只记得，我曾经水了大学三年，在大四终于又奋斗一把，终于把英语水平回到了高考时的巅峰状态。转过头拍拍你儿子的肩膀，深有感触地说：“努力学啊，结果不重要。”因为奋斗了之后，绝对不是白费精力，你得到的更高的价值是这个过程。