Fatigue Test

[@MrChangCJ]

love seeing real life examples and actual testing instead of just theory and formulae in the text book! Thank you!

[@cale31032008]

Yo también.

[@mertyigit4093]

the most explanatory video I have ever watched about fatigue, at least in basics! Thank you

[@Felipe-53]

What an awesome job we see here. Thank you very much indeed, I'm sure this video is impacting a lot of students like me. The world surely needs educators like you guys. Thanks a lot.

[@bhatsujatyousuf334]

The best ever tutorial video i had witnessed in past 10 years!! N

[@NMA_NoMoreAmmo]

Your videos are so clean and informative, without childish emotions or facial expressions. Keep informing us. Thanks.

[@ericjohnvelasco422]

I am not sure if you want to be a good day at work now and then I will be there for you to be a u

[@ericjohnvelasco422]

))))))

[@faisalbashir4563]

We truly deserve educators like you, great video overall.

[@lesedimantile3807]

I'm a first-year student at the University of PRETORIA doing Mechanical Engineering, trust me it was nice to watch this video as I will be working under these things.

[@MM-np4md]

Congratulations, I would've loved to be at your school but my application got rejected

[@AIFars]

I'm studying yes, but I'm REALLY enjoyed. Thank you very much for this effort.

[@rawipap9773]

Thank you! You just save my life from the mid semester test. : )

[@oblivious3862]

That was informative af and well illustrated,, Thanks for the neat videos you provide. *much love*

[@Akki420ish]

This is the best video I have seen on Fatigue testing. Good job.

[@shaileshjangid1909]

way of explaining the each concept is epic .........thanks for this video

[@rumdonuts9111]

I love your videos! The stress machine sounds like what anxiety feels like.

[@RYONPAK]

Best fatigue video ever

[@ai7229]

Do you have a report on the subject?

[@mahmoudmuhammad7525]

Really your explaning Flow is great and showing the real life tests is really so helpful Thanks alot Keep Going

[@parikshitpadture4122]

Excellent video with a good balance of theory and practice

[@srt1312]

a perfectly and well defined demonstration for fatigue

[@susanpinal8899]

Easy to follow! & real life examples. Thank you

[@vikalpluthra5404]

Thank you for this explanatory video. This was very helpful to understand mechanical Fatigue in material.

[@siddharthbenadi7966]

Best Explanation... 👏👌

[@venubarathan8391]

Impressed with technical content

[@deepakdilip1414]

Dammit mate, why I didn't find this video early!! It literally helped me understand what I was looking for in the last two weeks!!

[@jackdrdo]

Amazing video, by the real Life example understand very clearly and confidential 😃😃

[@karthikhs2569]

Excellent explanation of the concepts with practical scenario

[@Satyaki266]

Wow ! What a Video. All the things cleared. Thank u.

[@fahadimran4251]

science has not yet completely explained the complete mechanism of fatigue, the engineer must still design things that will not fail. In a sense this is a classic example of the true meaning of engineering as contrasted with science. Engineers use science to solve their problems if the science is available. But available or not, the problem must be solved, and whatever form the solution takes under these conditions is called engineering.

[@thehammurabichode7994]

Had to read it twice but I I got ya. Have a like, with lil peppercorns

[@88NA]

This is a very high quality video. I just subscribe to this channel.

[@shishirsingh3348]

awesome worth to watch

[@revanasiddappap635]

Very nicely explained with examples. Thanks

[@akashdileepgandhi7363]

Very nice description of the test including fracture surface analysis. My question is the failure is within gauge portion or outside the gauge portion. How to check the validity of the test. Akash from BARC Mumbai

[@MaterialsScience2000]

Answer to "Very nice description of the test including fracture surface analysis. My question is the failure is within gauge portion or outside the gauge portion. How to check the validity of the test.": In our fatigue test, we did not use a typical strain gauge, which is quite common in fatigue testing. Only in the so-called low-cycle fatigue testing are strain gauges used. In our tests, the fracture occurs within the cylindrical test region. I'm afraid validity testing is a long subject, far too long to explain here.

[@hermeswilliansantiagoflore4988]

Really interesting!!!, congratulations and thank you...:)

[@ashishkumarsenapati662]

Hats off..very well explained.. thank you..👍👍👍

[@blancaroca8786]

Obviously excellent job, so much better than cartoons or teacher memorized curves. Nice to see the result graph with statistical spread. Hopefully our critical car parts operate significantly under that! Just also wondering what happens using different frequencies for the loading. Is there some general trend?

[@MaterialsScience2000]

Answer to "Just also wondering what happens using different frequencies for the loading. Is there some general trend?" There is in principle little influence of the frequency of the load cycles for steel (and similar materials) at room temperature. Only the number of the load cycles matters. However, the frequency of the load cycles must not be too high, otherwise the specimen will heat up. It may be quite complicated at high temperatures.

[@naviddavanikabir]

great video. I need to do this test on PEEK, a rigid plastic. the standard we follow is ASTM 7791. knowing only the ultimate stress and with limited number of specimen, how should I choose the stress/strain level to find the endurance limit and to waste as little specimen as possible?

[@ajidamodaran]

Thank you for sharing

[@DoctorSkyway]

Very interesting, props for mentioning the enormous scatter those tests produce. It would also be great if you could do a demonstration of a rotating beam test.

[@MaterialsScience2000]

Answer to "It would also be great if you could do a demonstration of a rotating beam test": We had a rotating beam test machine long ago, but we do not have it any more ... sorry.

[@rathansagi6827]

Firstly thank you for such interesting and wonderful video..: i have developed rotating bending fatigue test machine.. results are quite satisfactory..

[@apm2649]

Wow this is just awsm. I love fatigue test in real life

[@chandansahu004]

Videos are very good.. Please make it for other characterization technique of materials like FTIR ,RAMAN ,TGA DSC etc..

[@MaterialsScience2000]

Answer to "Videos are very good. Please make it for other characterization technique of materials like FTIR ,RAMAN ,TGA DSC etc..": We would like to do so, but we do not have the appropriate experience in this area.

[@pratikprajapati267]

Excellent ever...

[@saifalino]

Thank you, This was of great use!

[@williamcechinguarienti2071]

Great video!

[@ShivamVerma-gq2sm]

Thankyou so much for this tutorial.... very descriptive!!

[@arnaudlheureux7238]

This video is perfect except for the comic sans

[@blancaroca8786]

What is comic sans? Without humor? To be honest I laugh and get excited at just seeing real and slightly surprising results. Those numbers he uses like millions of vibrations are just out of this world... science more fun than science fiction!

[@samuelspencer5047]

thank you for such a great explanation of fatigue test

[@kalsariyaajay7602]

Very nice video and perfect explained

[@taherbalasinorwala4751]

Can you please make a video on impact test and creep test.

[@alihassan1261]

very helpful video. i like your work keep it up.

[@amolkumbhar1108]

Awesome video....good explanation.

[@yasmeenhamdy53]

FANTASTIC VEDIO

[@iamkeystroke]

Wow, that was a fascinating video.

[@ziyadalgaboby3767]

good job, thanx

[@ACDroneDesignforPerformance]

Hi, could I use part of this video for my next video? It deals with the engineering of aircraft Panavia Tornado and I would give a short description of fatigue aspect. Thanks

[@MaterialsScience2000]

Answer to "Hi, could I use part of this video for my next video? It deals with the engineering of aircraft Panavia Tornado and I would give a short description of fatigue aspect. Thanks": Sorry, that's not allowed; we've had bad experiences. Good luck with your videos!

[@rajeshprasad101]

very nice video. will use it for my class.

[@mundo01]

finally i understand it , books are not able to show this.

[@方老師-k3q]

awesome, thank you so much!

[@-SanjaykumarM-gx4sz]

Very nice explanation

[@chandanpatel989]

great videos ...full of concepts

[@rubasarkez9917]

very helpful

[@bisisamosa2818]

Super video, neat explanation

[@arma_6872]

Thanks for your explanation. 👍

[@mohankumarn1606]

Do videos about work hardening, precipitation hardening

[@rajeev_kumar]

Very good video

[@1dundermifflinfinity]

Very helpful. Thank you.

[@stickerhppy]

Do a video about XRF ;) Awesome channel! Subscribed!

[@cemer1833]

I am doing a thesis.Can I learn the technical information of this test device?I would be most grateful if you would look into this matter as soon as possible

[@yagzozgor7043]

It is a perfect video but the first example - wire fractured by bending back and forth- has nothing to do with fatigue.

[@MaterialsScience2000]

Answer to "It is a perfect video but the first example - wire fractured by bending back and forth- has nothing to do with fatigue." At first glance, bending a wire back and forth seems to have nothing to do with fatigue. But they are very closely related. It has been studied very thoroughly. Fatigue phenomena can range from very severe plastic deformation (this is known as low cycle fatigue) to comparatively light loading (high cycle fatigue).

[@wajahata6481]

Very well explained..

[@mubashirhassan2772]

Good job... Please make more vedeos..

[@ace-rn3hn]

thank you , very helpful !

[@aboammarabdulqadir6470]

good knowledge for students

[@barryeastallen1638]

great video

[@sambenkamel]

great Video, thank you

[@andrewdolphin1198]

I think Fatigue threshold of an artefact of a specimen test particularly noticeable in steel and should not be highlighted as normal material behaviour. More on material behaviour rather than how the test machine works would be time better spent

[@MaterialsScience2000]

Answer to "I think Fatigue threshold of an artefact of a specimen test particularly noticeable in steel and should not be highlighted as normal material behaviour. More on material behaviour rather than how the test machine works would be time better spent": I principally agree with you comment. However, the idea of all our videos is to show the test methods primarily. To highlight the material behaviour in more detail would be the next step ...

[@subirbiswas2831]

very impressive... thank you

[@LongNguyen-qn3qn]

I love your videos! how can i calculate the spring. i am very instered it

[@MaterialsScience2000]

Answer to "I love your videos! how can i calculate the spring. i am very instered it": The most important point is to choose an appropriate resonance frequency of the spring-mass system. The spring is designed so that the resonance frequency is slightly higher than the intended test frequency. The machine is operated subcritically (below the resonance frequency) in the test.

[@shridharacharya134]

Well explained 🙏

[@randomgirl0707]

Great video thank you!

[@jakeshkumar]

Can u explain how to calculate the fatigue load (both tension and compression) and no of cycle before testing the product

[@MaterialsScience2000]

Answer to "Can u explain how to calculate the fatigue load (both tension and compression) and no of cycle before testing the product": The load for the first test must be intelligently estimated. At a mean stress of zero, one typically uses a certain fraction of the yield strength, say 80%. Then the test is started, and the number of cycles to failure is the result. Depending on the result of the first test, the load for the second test is reasonably determined, and so on. It is more complicated at other mean stresses, I am afraid ...

[@jakeshkumar]

@@MaterialsScience2000 so it's basically experimenting load on different lower than 80% load cycle and at maintaining cycles to which the maximum cycle can be fixed or the components fails ......

[@nilofarpathan665]

this is quite interesting!!!

[@SEVENR0Y]

Thank you for the knowledge that you bring to us. Can i ask for a 3d assembly of this machine if you're pleased?

[@MaterialsScience2000]

Answer to "Thank you for the knowledge that you bring to us. Can i ask for a 3d assembly of this machine if you're pleased?": Thanks, but, sorry, we do not have a 3d assembly ...

[@anglamchannel4533]

anh ơi em đang làm đồ án về thiết kế máy kiểm tra độ bền mỏi kiểu kéo nén cho vật liệu kim loại. Không biết anh có file tài liệu hoặc lắp ráp nào không ạ

[@syahmizulkifli248]

Hi, thank you for this video. Can I know is this test considered under ASTM ?

[@MaterialsScience2000]

Answer to "Hi, thank you for this video. Can I know is this test considered under ASTM ?" Principally yes, but you have to check the details for testing in the appropriate ASTM standards.

[@lernfleissiger2096]

nice video, danke. I want to ask, can we use the specimen's shape in a flat (plate) form?

[@MaterialsScience2000]

Answer to "can we use the specimen's shape in a flat (plate) form?": Yes, the only trouble is the danger of buckling under compressive stresses. So thin plates should rather be tested within the tensile region.

[@lernfleissiger2096]

MaterialsScience2000 thanks sir for the suggestion. I am sorry to ask this, do you have some references about fatigue testing of Aluminium?

[@Varunkumar-dd1tb]

Totally perfect t explain

[@05032885741]

thank you

[@sivachidambaram1983]

Can you please tell me the make of machine. I am interested in procuring this. Also I have doubt, how did you maintain the constant load and displacement.

[@MaterialsScience2000]

Answer to "Can you please tell me the make of machine. I am interested in procuring this. Also I have doubt, how did you maintain the constant load and displacement." The machine is an old testing machine that has been completely refurbished and equipped with a computer control by ourselves. There are some similar machines refurbished by commercial companies on the market. The constant load is maintained by computerized automatic control via measuring the force and adjusting the force by altering the speed of the spindle with the rotating mass.

[@Shumayal]

Interesting! I wonder how do they test the material used for building the very first fatigue testing machine :P haha... what a conundrum indeed :P

[@nikola176]

Hi, i am working on project for university on exact this peace of machine. Can you tell me how to determine spring stiffness and how long and how i can conect it with eccentric load?

[@MaterialsScience2000]

Answer to "Hi, i am working on project for university on exact this peace of machine. Can you tell me how to determine spring stiffness and how long and how i can conect it with eccentric load?": This is an interesting question that unfortunately cannot be explained in a few sentences. Some ideas: Determine the resonant frequency, and then operate the machine in the subcritical range. You need two springs and special bearings.

[@cesarescobar9679]

Did you fabricate the device to grip the specimens to tension and compression test? This fixturing is the best option for tension and compression test for cylindrical specimens? Thanks

[@MaterialsScience2000]

Answer to "Did you fabricate the device to grip the specimens to tension and compression test? This fixturing is the best option for tension and compression test for cylindrical specimens? Thanks" The grips in the machine (as shown in the video) were supplied by the manufacturer of the machine. This is a good method, but many other grip designs are used: hydraulic grips, threaded ends, ... Properly designed, all of them are good. Sorry for the late reply.

[@cesaresc8525]

Thank you for your reply, for the conditions of our equipment, threaded ends were not one possibility, for this reason, I used this video and designed grips for our machine. Thanks again

[@venugopal-gi9jt]

And what are lengths of different specimen material that can be used for this fatigue test

[@MaterialsScience2000]

Answer to "And what are lengths of different specimen material that can be used for this fatigue test": There is (almost) no limitation to the length of the specimen, as long as the machine is able to grip the specimen and as long as there is no buckling under compressive stresses.

[@HungNguyen-98]

loadcell horizontal so the force is correct when the loadcell must support additional clamps?

[@MaterialsScience2000]

Answer to "loadcell horizontal so the force is correct when the loadcell must support additional clamps?" Yes, the force is measured (almost) correctly. The typical largest error comes from the mass of the clamp on the left side and its inertia. But this is a very small error, because the left clamp hardly moves due to the large stiffness of the load cell. The gravitational forces are practically all compensated.

[@aronnilsson5343]

Excellent

[@mohammadmahdiahmadpour264]

perfect👌

[@mehmettuncerdem2721]

I have a project to design such a device, what should I pay attention to?

[@MaterialsScience2000]

Answer to "I have a project to design such a device, what should I pay attention to?": There are actually many points to consider. Among the most important are: - The machine frame is not very easy to design, pay attention to all the bearings - Measuring the force is quite tricky; you have to measure the force with high frequency and then extract the extrema - The most important point is the automatic control of the sample force so that no instability occurs. I'm sorry, I can't go into all the details, they are way too complex. Good luck!

[@nikola176]

Hi, how can I determine power of electromotor which I need. I have a max force on sping and spring stroke. Thank you.

[@MaterialsScience2000]

Answer to "Hi, how can I determine power of electromotor which I need. I have a max force on sping and spring stroke. Thank you.": This is an important question that is not easy to answer. The electric drive only has to supply the power loss, i.e. the friction and the power absorbed internally. This is very little, in our machine the electric drive needs less than 200 W. One of the great advantages of this type of testing machine!

[@hamedismail5703]

الف شكر وربنا يوفقكو

[@tsshakthivel175]

Nice Demonstration

[@d218dishatripathi2]

Thank you.

[@rachidmeghnine4081]

hello , Can you explain me how the movement of echo of the spring is generated?

[@MaterialsScience2000]

Answer to "Can you explain me how the movement of echo of the spring is generated?" The oscillating mass is stimulated by the rotating imbalance. By varying the rotational frequency of the imbalance, the oscillation amplitude of the mass (and as a consequence the test force) can be controlled. The machine is operated in the subcritical part of its resonance curve.

[@leonecho1979]

are there any signs that fatigue failure is about to happen in, say, a bicycle?

[@MaterialsScience2000]

+Leon Echo Answer to "are there any signs that fatigue failure is about to happen in, say, a bicycle?" In most cases: no, since the fatigue cracks are very narrow and it is difficult to find them. Typically, they can only be detected by nondestructive testing

[@sinakeshavarz9839]

it was amazing. thanks for dis