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Mechanics Channel by Mark Barkey
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Добавлен 28 дек 2014
Mechanics is the study of how objects (structures, materials) respond to load. I am a Professor at the University of Alabama, and have degrees from from the University of Missouri-Rolla (now Missouri University of Science and Technology) in Engineering Mechanics (BS with a minor in mathematics) and from the University of Illinois in Theoretical and Applied Mechanics (MS and PhD).
My Mechanics Channel is a place for me to put my lectures on-line to reach a broader audience than I can in just in my classroom. I have started with Mechanics of Materials, but now that is complete, I intend to make videos for aspects of elasticity, plasticity, fatigue, fracture, experimental mechanics, applied finite element analysis and other subjects that I have taught and researched.
My Mechanics Channel is a place for me to put my lectures on-line to reach a broader audience than I can in just in my classroom. I have started with Mechanics of Materials, but now that is complete, I intend to make videos for aspects of elasticity, plasticity, fatigue, fracture, experimental mechanics, applied finite element analysis and other subjects that I have taught and researched.
AEM 535 FEA 01 2022 24inch schedule80 ABAQUS
Analysis of schedule 80 pipe with ABAQUS 2022 version
Просмотров: 559
Видео
AEM535-FEA 01-2022_24inch_schedule80_Hypermesh
Просмотров 5032 года назад
Creation of schedule 80 Pipe; 24 inch OD; updated for Hypermesh 2022
AEM250 distance introduction FA23 SP24
Просмотров 3052 года назад
For AEM 250-distance students to see how to access the course shell (Blackboard) and explain how the course will be conducted.
AEM 637 plotting plate with crack stress distribution
Просмотров 5742 года назад
plotting crack tip stress field; range of applicability; comparison to plate with a hole
AEM 637 plotting plate with hole stress distribution
Просмотров 1,1 тыс.2 года назад
using excel to plot stress distribution for elasticity solution of an infinite plate containing a hole
AEM 637 Problem 4 18 6
Просмотров 5652 года назад
Checking 3-D elasticity equations for Mechanics of Materials stress/strain fields
AEM 637 Problem 4-7.1
Просмотров 6052 года назад
Theory of Elasticity: Deformation fields for tension-torsion stress state.
AEM 637 Problem 4-19.4
Просмотров 4272 года назад
eigenvalues and eigenvectors for elastic torsion problem, circular cross-section
AEM637 generalized plane eigen problem example
Просмотров 8662 года назад
AEM637 generalized plane eigen problem example
AEM 637 Problem 2-16.2
Просмотров 1 тыс.2 года назад
Example problem/homework problem, determination of displacement fields from strain fields; plane elasticity; small strains; system of partial differential equations
AEM 637 overview for distance students
Просмотров 4343 года назад
AEM 637 overview for distance students
2021 Plasticity normality flow rule in regular stress space
Просмотров 1,5 тыс.3 года назад
2021 Plasticity normality flow rule in regular stress space
28 Intro to multiaxial plasticity for fatigue analysis
Просмотров 6653 года назад
28 Intro to multiaxial plasticity for fatigue analysis
26 dicussion of Socie multiaxial fatigue damage
Просмотров 7243 года назад
26 dicussion of Socie multiaxial fatigue damage
25 introduction to multiaxial fatigue
Просмотров 1,9 тыс.3 года назад
25 introduction to multiaxial fatigue
24 4 30 partial solution cyclic neuber
Просмотров 1,3 тыс.3 года назад
24 4 30 partial solution cyclic neuber
23 vehicle design process and proving grounds
Просмотров 2993 года назад
23 vehicle design process and proving grounds
Thank you
happy studies!
the value on point A = 500, is this assumed or can be determined before?
I want the pdf of lecture please
Thank you so much for this content, Prof. Pls, how can I join or visit your personal website website to get the material file used in this lecture. Awaiting your response, Sir.
which book do you refer sir ?
Thank you so much for great kectures. Just a ailly doubt i always havea is whatbis the difference between in the subjects theory of elasticty\plasticity and continuum mechanics?
Continuum Mechanics is a general approach for all continuous media--solids, fluids, deformable dynamic bodies, etc. You can think of elasticity being continuum mechanics specialized to elastic materials, and likewise plasticity. Historically, however, elasticity and plasticity come first; then the more generalized framework of continuum mechanics was developed.
can you please send me this inp file ,
why do we also multiply by the transpose?
this was a great video and a solid explanation, I was looking for a way to always find the principal directions for the saint venant problem !
Hi professor Berkey, I have a quick question, I find your courses really interesting keep up the good job. My question is, what is the source or reference for the SN curve equation you showed for steel Ferrus metal (1.62*Su*N^-0.085). And also would that be a feasible equation for assessing the fatigue of a steel plate? Thank you so much.
I don't recall the original source, but I lectured from Bannantine, Fundamentals of Fatigue Analysis. It would be referenced there. It is an equation you might use if nothing else is available. If you have actual data then use it. Happy studies.
It was a great explanation. I am wondering why the components of shear stress in radial direction is not considered? As its also making angle dtheta from the radial direction.
Sir,, Volume is very low , can you please try to improve it
Sorry, I am not able to remake any videos at this time and any post processing improvements that I could do are also ones that you could do. Happy Studies!
@@mbarkey.mechanics ok Sir.. and Thanks for the great video, it helped me.
Thank you very much sir your content has been helping a lot lately in my studies
Thank you so much for taking the time to share your knowledge with us.
Thanks !
Hi Mark Barkey, that's a very classic explanation there. I would love to know more about your work in this field for my comprehension.
Great lecture, thanks a lot.
Thank you Sir for this interesting fatigue course
Thanks Dr. Mark.
put your mibile number here.
Sir, if the body undergoes pure translation and rotation then will the Jacobian be 1? Since the body has not undergone any deformation that is d(xi) = dx, which means the J should be 1. Please provide your input on this. Thanks!
(rigid) Translations are easy to see that J=1. You have to be careful with equations for rotations.. If the equations are not written in a certain way, you may not notice that the points go through a rigid rotation. You have to be careful with standard FEA codes. Explicit codes would usually account for large deformations and translations.
Hi professor Barkey. How can we tell when we have a stress singularity rather than a real stress concentration? I've run FEA models where I always get a crazy amount of stress in connections between elements. But those are really small localized points, some people ask me to crazy reinforced those areas to see if we can get rid of the high peak in stresses. In my mind that peak would not be important since it's in very small localized point and probably von mises it's not even applicable due to the constraint in connections and the possible development of tri axial state of stress. What do you think about it ? how would you approach those issues? Thank you so much
Crack like stress distributions are distinctive. You can see some in the next series of examples. Connections, MPCs, and point constraints can all cause local stress disturbances and are hard to alleviate. Auto companies will often use standard element sizes and connection techniques so that they deal with known modelling errors.
Dear Prof Mark, first Thanks a lot for your videos, I have a small question.. at 22:20 what does it mean look at half life and why?
If the specimen lasted 50,000 cycles, the half-life would be 25,000 cycles. Most materials would be stabalized by then and you would examine this hysteresis loop. Of course, to find the half-life cycle, you must first test to find the failure cycles.
Thank you very much for your fruitful lectures. Could you please give me your email address? Actually I am working on fatigue analysis of mooring line. I have already got load history. But i can't determine the number of cycles as i have several same stress levels in diagram. I would be grateful if you give me your email address. Thank you
Great.
Great lecture, thank you a lot.
thanks--happy studies
legend
Does the method for closing the non closed hysteresis loops (from 15:) is equivalent to apply the rainflow counting to the mirrored signal ?
By mirrored signal, do you mean repeating it back to largest peak? If so, no, since for unclosed loops the damage is usually taken to be one-half the closed loop damage. If you mean something else, let me know. But I don't think any method of artificially closing unclosed loops and counting half damage would be like any other technique.
Thanks Prof. Mark!
Thanks for your video. It looks like it requires a lot of manual calculation. Is there a table of these figures readily available for each different type of beam?
yes, for standard shapes there are tables. However, by understanding the calculation, you can learn why the beam is designed the way that it is.
Thank you
Thanks that you give me such a nice lectures. I feel that your ingenuity enlighting every dark corners of my knowledge.
thank you
Thank you so much!!
wonderful lecture, thank you professor.
Thanks--happy studies--
Great lecture.
Dear Sir, thank you very much for very useful lectures. I have a question if you could please answer. For a case of simply supported beam subjected to UDL, the moment is zero at the supports but when writing boundary conditions are vertical faces near supports, we take the integration of bending stresses equal to zero. Why cannot we directly put bending stress expression to be equal to zero? Thank you in anticipation.
I think the answer you want is based on the mathematics: We have taken a 3-D problem and reduced it to 2-D, then invoked a stress function approach to make that math easier...so we have given up some elegance for practicality. But consider the deeper philosophical answer: even our 3-D problem is a representation of what we think of reality...find a actual simply supported beam with a uniform distributed load and look at the supports--which are a finite width--what location there has a totally zero bending stress distribution? Maybe that approximation of no net resulting bending moment is OK after all! We can continue this discussion through to finite element analysis, and I can counter with relativistic mechanics and quantum mechanics. And even then we end up with the same question--is our simplification good enough?
@@mbarkey.mechanics thank you Professor. I get it now
Dear Sir, thank you very much for very useful lectures. I have a question if you could please answer. For a case of simply supported beam subjected to UDL, the moment is zero at the supports but when writing boundary conditions are vertical faces near supports, we take the integration of bending stresses equal to zero. Why cannot we directly put bending stress expression to be equal to zero? Thank you in anticipation.
Really great lecture, thank you a lot.
Excellent videos, I hope you haven’t given up making them.
Thanks. In my current role as Department Head, my duties have not allowed as much time for video development...but I will get back to it some day again. Happy Studies.
Thank you for amazing explanation. Can you please refer me a book for this.
I am thankful for your lecture series Professor. Your lectures are very instructive, helpful, amazing.
may i know, what is distance between base plate and bottom of column
Timestamp 28
Can mem never be greater than 2? I have about 500points to process and there are instances where my memory is greater than 10. Also, can you please tell me how to count half cycles ?
Yes, the memory storage for can be greater than 2. ASTM rainflow forces the start of the sequence with the largest peak (or valley) and so there would never be any un-closed loops in following this procedure. However, if you are doing 'real time' rainflow processing then there can be instances where you do not have control of the start of the time history. This case is discussed in my lectures. The usual implementation is to go ahead and close all un-closed loops and assign half damage to those loops that were artificially closed. In the German literature, this is known as a 'residue' of the time history and you can find literature addressing this in detail.
@@mbarkey.mechanics thank you for the response! Can you please point me to the lecture which speaks about rainflow processing in 'real time'. Also for the residual cycles, is there any standard algorithm to follow?
@@prithvi-y4v I don't remember which lecture, but the procedure is just as I have described above.
me about to cry becasue this is so much better than my lectures( still grateful for both tho)
Hi Mr, at 33:10, would the di be in the small circle?
di is the inside diameter (the hole) for the tube.
i love this page! THANK YOU, if i have any questions r u able to reply? i am studying this currently! ill look into all videos of yours.
Sure, go ahead. Happy studies.
Have you not thought about deriving this using modern notations? I think a lot of confusion can be avoided in this way.
My lectures are prepared for the audience I give them to, and the notation used varies with that audience. I encourage you to make your own lectures to your satisfaction.
Great explanation! BTW, at 35:00, I think we should write duj/dei(ej)(ei), instead of duj/dui(ei)(ej).