Thank you very much professor Barbero. I apreciate your scientific sharing

@EverBarbero

3 жыл бұрын

You are very welcome

I would like to see how this technique would work in Layered CFRP model.

Thank you very much for the tutorial professor Barbero. The problem I have in my case is that Abaqus exits with error and says that the czm elements are distorted when I apply the tie constraint

@EverBarbero

3 жыл бұрын

It could be that some detail was not so clear in the video and caused you to make a mistake. For an exact line-by-line procedure you can check the pseudo-code in the textbook barbero.cadec-online.com/feacm-abaqus/index.html

Thank you Professor Barbero, is there no need to define hard contact ?, because in my 3D model the adhesive look like sank to my concrete in high loading

@EverBarbero

3 жыл бұрын

The cohesive elements have stiffness, E/Enn, they should not sink. Please check if the magnification factor in the visualization is huge (look at the bottom of the workspace); it may be it exaggerates the deflection so much that it looks like sinking.

Sir..excellent video.. I have added some cohesive interactions in my model. Now my model is taking too much time to finish one increment. It may take even one month to complete the job.. I am modeling a unit cell of unidirectional composite.. Are there any methods to reduce the running time sir?

Thank you very much for the tutorial. What I did not quite get is why the cohesive thickness in the result is so small, when it was initially defined to have a thickness of 1 mm?

@nicolas9408

2 жыл бұрын

Okay, sorry, you explained this on page 367 in section v in your book. Then I would like to ask what the distance tolerance of 0.002 in this constraint means? Is it referring to a tolerance of 2 mm or 0.2% of an mm? The Abaqus documentation did not clarify this for me. Also, since the constraints enforce an initial thickness of 0 mm, does the part thickness matter at all, or is it really just a convenient visualization procedure? In your book, you argue that a traditional stress-strain relation is not feasible, due to the vanishing thickness of the cohesive element. This is why we use the traction-separation law, which reads t = K*delta. When t is of unit Pa, and delta is of unit m, should K not be of unit Pa/m? Your book states the unit of E/K to be Pa. Would that not mean that delta is in fact a strain? I think my confusion comes from the fact that a cohesive section is defined with an initial thickness of default (assumably 1), nodal coordinate, or specified. To my understanding the displacement measurement is transformed to a strain based on this assumed initial thickness, e.i. that a displacement of 1 would be a strain of 1. Could you verify this, please? Depending on this initial thickness, the element stiffness would need to be scaled.

Dear professor what is the significance of opening reaction force vs opening displacement graph is it related to energy release rate if opening force is high then energy release rate is also high. Thank you

@EverBarbero

3 жыл бұрын

Please see my reply in 10.2

Thank you professor. Do you know have to solve the theoretical solution for the double cantilever beam?

@EverBarbero

3 жыл бұрын

Yes, there are papers, but they always need some experimental data as input, say compliance vs crack length, or crack length vs load, etc. or you have to know the Gc.

@yuwang7131

3 жыл бұрын

@@EverBarbero Thanks Professor Barbero

Dear Professor, I am unable to find the python script from your website. Can you please, send me the link.

@EverBarbero

3 жыл бұрын

It is posted now, here: barbero.cadec-online.com/feacm-abaqus/Examples/Chapter_10/Ex_10.1/

@ruchirshrivastava6638

3 жыл бұрын

@@EverBarbero Thankyou very much sir.

Dear Professor, which will be an assessment to predict composite failure, like as you said laminate failure criteria(TMSC) or we should directly go to DDM or CZM, or all is necessary for analyzing. if I predict failure by TMSC will it sufficient. Also in some composite, there are fatigue failure criteria. Please, professor, enlighten about, to decide failure which way should go, all aspects should cover or only one criterion like TMSC is sufficient.

@EverBarbero

3 жыл бұрын

I replied to a similar comment before. Basically TMS, max. strain, etc. are OK for preliminary design. After that, we do detailed analysis using Abaqus.

@VivekDhimole

3 жыл бұрын

@@EverBarbero Dear Professor yes that we got. Professor, you have made one video for using TMS but it was for lamina. May you describe TMS for laminate for primary Design in future videos as the application, also how normalized factor and knockdown factor works for strength and TMS. Thank you, Professor

@EverBarbero

3 жыл бұрын

Vivek Dhimole please remind me in which video I used TMS?

@VivekDhimole

3 жыл бұрын

@@EverBarbero Dear professor, in the same video at last in which you described UMAT subroutine for Abaqus. Named is ( How to write an Abaqus Umat)

why not we creat a refrence point?

@EverBarbero

2 жыл бұрын

I guess you could do that. If you try and you get the same results, please tell me exactly how you did it, what is different. Thanks.