Really a great video with in depth concept and knowledge sharing

very comprehensive and informative...thanks

Really helpful in understanding the basics and modelling a composite with cohesive layer

Very helpful, Sir! Thank you

it's very important, thank you for sharing

Dear Mr.Khan, You may not have realized but let me tell you this, your video has definitely help me to understand some of the things that was confusing to me. Thank you so much.

@SanaanKhan

5 жыл бұрын

Am glad that you are happy.

Hi Sanan , thank you for this video. I found it very useful. I am trying to model a crack within a composite hydrofoil/airfoil shape. What do you think would be the best approach? The part is 50mm thick and has a lot of plies , also has ply drop offs because of curvature. Thanks so much

Hey sanan, great Video, learnt sth new with the zero thickness elements! I am doing Riveting of Cfrp-metal Laminate. What do you recommend for modelling the CFRP? Should I also use the zero thickness cohesives ?

thanks sanan for this amazing tutrial , it i really useful though i have a problem in my project is that im not able to find the whole material properies as for concrete,uhpc,strands,bolts i hope u can help me with that

Hi Sanan, Thanks for all great tutorials. I am trying to use such a cohesive model in a 3-pt bending test of a 0-90 composite. However I take an error messages like: 'THE THICKNESS CALCULATED FROM GEOMETRY IS EQUAL TO ZERO FOR ELEMENT 12001 INSTANCE COMP-0-BOT-1. THIS IS NOT ALLOWED IN Abaqus. A NON-ZERO THICKNESS VALUE SHOULD BE SPECIFIED IN THIS CASE' I think that I should give a thickness to cohesive layers but I cannot find editing the layer thicknesses. Moreover When I give a very small thickness, should I change point-to-point assembly in between 90 and 0 layers?Thanks in advance, I wait for your answer.

dear Sanan, thanks for the video, would you mind please telling me how can i delete this offset element which has defined as glue?

Thanks Sanan for sharing worthy video. I am trying to model the cohesive layer between two shell elements(Parts). But I am not able to define the cohesive section to the offset mesh. Can we insert the cohesive layer in shell elements, with help of steps which you taught in this video??

Thank You Sanan for your well explained video. But i m right now facing difficulty in putting the initial values for composite. Since my composite is of woven glass fiber and your video is fully dedicated to unidirectional fiber. How to go about woven glass fiber as in no direct formula is available. It will be of great help if i you can fetch me on how to enter the engineering constant values and values pertaining to Haskin Damage criteria. Thank You. Waiting for your positive response.

Is the stacking direction specified during the composite layup correct ? Isn't it supposed to be along the thickness of the composite layer ?

Hi Sanan. which one is better for modeling hydraulic fracturing in a geothermal reservoir CZM or XFEM ? Could this videos help me to model hydraulic fracture as regard you modeled it for a composite? i need to model a subsurface .

Please give me the documents about cohesives elements on this video or the same, I am using ABAQUS to simulation the impact composite under low velocity and using cohesive element bettwen layers like you do , but i dont know what is does cohesive element properties? ( E/Enn, G1/Ess, G2/Ett, Quads damage....). Where did you found this?

sir can you suggest,if i want to do analysis of plate having multiple holes at the boundaries.should i model them in starting while creating geometry for each ply or after joining the layers by cohesive elements

Hello Sanan!. Thanks for sharing worthy video. Can we model the cohesive layer with shell element? I have created a offset shell mesh but I am not able to define a cohesive section to the cohesive shell elements. How to create a cohesive shell section?

hi, Sanan, I want to simulate DSR. its two parrallel plates in between bitumen. the top plates rotates creating shear stresses in the bitumen layer. i have problem with the interface(steel to bitumen). i have to use bottom up technique but then in the interface i get error while using bottom up. can you please advise me how to do it properly?

Thank you, sir, for this excellent explanation. Sir, I am currently working on modeling of 3D printed concrete elements, can I implement cohesive elements between the two printed layers, since there is not any epoxy or adhesive material between the consecutive layers (layers are directly stacked on each other), I've a doubt whether it is relevant to implement cohesive elements or direct surface to surface contact is enough. Kindly give your suggestion, sir.

Respected sir, I have followed this for Tensile damage analysis of composites. It resulted in an error. I was willing to see damage in each ply. When I use solid feature, Hashin criterion doesn't support. And when I use the 2-D Model, ply failure could not be seen. Apart from VUMAT, is there any way, to see this?

Hi, Sanan. I got a question. I am simulating impact test on composites. I am getting excessive distortion error. Would yu help please.

hi sir. h need to model a composite with three different layers. the model have 2 cracks. in "property" in "mechanical elastic" tap, i dont know if i should use traction or lamina? could u help me? please

Assalamoalaikum Sanan! Can you splve an example on fatigue crack growth and upload it on youtube? That would be very helpful for my project Regards Zaman

do u know how to simulate a wedge peel test using cohesive zone modelling?

What if we have to model an adhesive joint with adhesive layer of finite thickness? Still the the thickness of cohesive elements will be zero?

Hello , Can you please help with the properties input for the fiber reinforced composites and how to derive them . I have to do my project related to RC beam with frp

in the first 40 mins it was good but when you deal with cohesive element, you messed it up.. i'm pretty sure if you run it, it will give error..

Hi, Sanan I have watched a couple of your videos and I really appreciate your content, especially because you explain why certain things are done in ABAQUS. I was wondering if you could make a video to simulate tensile test for "adhesive single lap joints" using cohesive elements. Thank you

İ haventt eatched the vid, but u look like an expert, is it ok to use c3dr8 element for meshing of a mortar? ,Do u think? İ use surface based cohesive behavior instead of coh. Elements.

thanks a lot sanan

Where can I find your other lectures ?

Thank you for the tutorial, specially for taking the time to explain various theoretical concepts related to the constitutive behavior of cohesive elements. Unfortunately I'm also getting the error mentioned by other users: "THE THICKNESS CALCULATED FROM GEOMETRY IS EQUAL TO ZERO FOR ELEMENT 8006 INSTANCE COMP0-1. THIS IS NOT ALLOWED IN Abaqus. A NON-ZERO THICKNESS VALUE SHOULD BE SPECIFIED IN THIS CASE" There must be some step missing. Could you review this issue? Best regards.

@ib_parametres724

4 жыл бұрын

This might be late, but I think if you select "Analysis Default" for "Initial thickness" at 55:10, you might solve that problem. Best.

Thanks Sanan for your helpful video detailed explanations. I tried the same model as you generated and I get this error :"THE THICKNESS CALCULATED FROM GEOMETRY IS EQUAL TO ZERO FOR ELEMENT 8006 INSTANCE COMP0-1. THIS IS NOT ALLOWED IN Abaqus. A NON-ZERO THICKNESS VALUE SHOULD BE SPECIFIED IN THIS CASE" Do you have any suggestions how I can fix it?

@komiser20

5 жыл бұрын

سلام میتونم ایمیلتون داشته باشم سوال دارم در مورد متریال ها

can you show procedure of encased stone column in abaqus

Thanks Sanan

How can I apply the same manner on truss element (bar) and 2d element (concrete) because I need to define the bond between concrete and steel bars?

@tawfee23okasha

7 жыл бұрын

im trying to do the same thing for a 3D case. how did you define the bond stress vs slip curve?

Hi Sanan, Why have you used Traction for the Cohesive element material properties and not isotropic ? And how to get the peel stress and shear stress values of the adhesive from what test equipment can we get these values ?

@SanaanKhan

4 жыл бұрын

Very interesting question. Actually cohesive behavior is a node failure property and not material property. Hence Isotropy is used for the elements. And traction separation law for failure of nodes because of displacement.

Hello is it possible to do transverse cracks with the same methode ?

Hello sir , This is Ashutosh Bangre I am working on cohesive zone modeling but the problem is it is not accepting hashin damage criterio . Please help me in this

Hi Sanan, Thank you for sharing a video. Can you tell me how to generate cohesive elements in case of 2D model. As we cannot apply this method for 2D

@SanaanKhan

9 жыл бұрын

for a 2D case partition the small area and apply the element and property to it.

@yongqi914

5 жыл бұрын

@@SanaanKhan Hello Sanan. Can you explain more about how to model it in 2D please? Thank you so so much.

@SanaanKhan

5 жыл бұрын

@@yongqi914 the process is same for 2D

@yongqi914

5 жыл бұрын

@@SanaanKhan Would you be able to give me some advice on how to model masonry structure? I'm considering bricks: lin-elastic and interfaces: cohesive elements at the moment.

Hi, Is it possible to apply a shear on cohesive elements ?

@SanaanKhan

4 жыл бұрын

Shear behavior is taken care in the mode 2 and mode 3

how to offset mesh for independent part

Where did you get the values for the fracture energy? I am struggling to find any anywhere

@davi_brt

5 жыл бұрын

Hi, have you found a way to calculate the four required values of the fracture energy? I found in literature that fracture energy is connected to the dimensions of the specimen that we are considering

@ashrafkamal1190

5 жыл бұрын

www.2kornucopia.com/pdfs/Diehl_Elastic_Cohesive_element_AUC2005.pdf

Hi sanan, thanks for your valuable video..i'm using version 6.13.while i tried the same model, i got the following error.. "THE THICKNESS CALCULATED FROM GEOMETRY IS EQUAL TO ZERO FOR ELEMENT 8001 INSTANCE COMPO-45-1. THIS IS NOT ALLOWED IN Abaqus. A NON-ZERO THICKNESS VALUE SHOULD BE SPECIFIED IN THIS CASE" how I can fix it? Kindly reply me.

@sjoerdovergoor1424

8 жыл бұрын

+david yesuraj Hi David, have you already worked out a solution? I am experiencing the same problem.

@yesurajd7044

8 жыл бұрын

Not yet find the solution...

@santiagorestrepo8662

8 жыл бұрын

+david yesuraj same error, has anyone come up with the solution?

@santiagorestrepo8662

8 жыл бұрын

+david yesuraj +Sjoerd Overgoor Finally came to a solution! The trick is to select "Use default analysis" when asked for the initial thickness instead of "Use geometry coordinates".

@lioutsiv8

7 жыл бұрын

i did what you propose but i get an other error :Time increment required is less than the minimum specified. The solution does not seem to converge. Any suggestions?

Hi Sanan, when explaining the input data to the "traction" behavior you show how E_nn=K_11 is derived and mention a paper in which this is explained in detail. I couldn't find the author. Could please write down his full name or the year of the publication. Thank you.

@aravindaero619

7 жыл бұрын

The paper is called : ''An engineering solution for mesh size effects in the simulation of delamination using cohesive zone models'' from Turon.

hi Sanan , thanks for this great video , I want to ask you , why did you use continum shell element and not 3D stress element ?

@SanaanKhan

8 жыл бұрын

3D brick elements are not supported with hashin failure model

@hajerboussetta2823

8 жыл бұрын

+Sanan H Khan and if i use an subroutine umat , what kind of element i have to use ? and can you explain to me , what is the utility of hourglass stifness , and what is the difference between element with reduced integration and another without ( C3D8R and C3D8 for example) ? If you have any support tha can help me to understand all this , i will be very thankful for you Sanan

Hi Sanan, Thanks a ton for sharing this video. I have a question which is not related to this video. I have a beam with with bolt. Step1 is pretension and step2 is bending load. the model is converging for pretension but not to bending. it is giving error as "ELEMENT PART-12-1-LIN-2-2.4628 IS DISTORTING EXCESSIVELY. CONTACT PAIR (ASSEMBLY_FLEX_BOLT_SURF1,ASSEMBLY_BOLT_THRU_SURF1) NODE " Please suggest me how to resolve this issue. thanks in advance.

@SanaanKhan

9 жыл бұрын

Whenever the element is unstable w.r.t stiffness matrix, it distort excessively. There are many reasons for the same. If you are modeling a non linear analysis try adding damping to a system. If not, try refining the mesh by choosing advancing front algo. Check the units of property given especially density and stiffness. Also, try reducing the loading rate. If the elements distort at the beginning of the analysis, excessive loading rate is the cause of it.

@g1sati2

9 жыл бұрын

can you share your mail id ...? I would like to connect with you. thank you very much for your suggestions. I have already added damping to the system( Control Stabilize automatic). Loading rate is also very very low I mean first increment is 1/100th.I can send you msg file to you for full detials. Thank you once again.:)

Hello Senan, i have a question , am not sure if i missed this , but why have we created diffrent parts for each ply/ layer? cannot we just create one part and distrubite it into several lazers and indicate the stacking sequance using composite layup and the number of layers ? and in case we used composite layup method ? how would we do the cohesive elements part ? thank you in advance

@SanaanKhan

2 жыл бұрын

Yes but then the delamination between the ply will not be possible. You need to select the ply surfaces to give delamination.

@mahaelsaeid3713

2 жыл бұрын

@@SanaanKhan thank you for your quick responce, then am quite confused, in what cases then would the comosite layup method be usefull?

@mahaelsaeid3713

2 жыл бұрын

@@SanaanKhan hello again, I have few more questions. I have constructed a simple tensile test model for my undefeated composite laminate, and I have calculated the reduced E11 ( from the stress starin curve along the fiber direction) However, I wanted to validate that my modelling approach was correct, so I thought of analytically calculating the general stiffness matrices (ABD) usinh a python code, and compare it with the general stiffness matrix of the abaqus model after extracting it. And now am confused, are these the right approach to validate that my simple abaqus model is correct? All I wanted to do was to check that my reduced E11 ( from the abaqus model ) is not so far from the value Calculated analytically. And also am not sure, if there is a way to extract the general stiffness matrix out of abaqus? Because I have tried a couple of methods I found on goolge but they didnot work. So my question is, if you can recommend a method for me to validate that my abaqus model , please do. And , if you can expalin to me more what are the values that I should validate against each other, will be great. Thank you in advance

Hi Sanan! Iam working on a 2D model simulating a cutting operation on a metal matrix composite where I have to use cohessive elements to simulate the interface between particle and matrix, so any tips to model cohesive elements in this case. And thanks for this video..it did clear many doubts i had :) Waiting for your reply !!!

@SanaanKhan

8 жыл бұрын

+Abhilash Pillai A very similar approach goes for the 2D case as well.

@AbhilashPillai225

8 жыл бұрын

+Sanan H Khan actually sir... The main obstacle is that in my case I need to model cohesive elements over a circle... Any leads sir plz???

@SanaanKhan

8 жыл бұрын

use edge to edge interaction (available in 6.14) and cohesive surface

@khaderhamdia2071

8 жыл бұрын

+Sanan H Khan, Great work. I am also working on similar system of 2D modeling for matrix reinforced by circular particles. I still facing difficulties in creating surfaces. Any tips. +Abhilash Pillai, did it worked with?

thanks

salam, Sanan, thanks for the tutoriel. I tried to apply this example, but I did not succeed. I'm getting the error messages : THE THICKNESS CALCULATED FROM GEOMETRY IS EQUAL TO ZERO FOR ELEMENT 8011 INSTANCE COMP-0-1. THIS IS NOT ALLOWED IN Abaqus. A NON-ZERO THICKNESS VALUE SHOULD BE SPECIFIED IN THIS CASE.

@ManishSharma-zh2iu

4 жыл бұрын

Hi, I am facing the same problem. may I know how you resolved it

good

Great video. Congratulations. Can you help me with a video related to sand Production. I really appreciate all your support and help. Thanks in advanced.

s'il vous plait,j'ai trouvé un problème au niveau des propriétés de l'élément cohésif dans le cas d'un ABQUS EXPLICITE . ils ont affiché l'erreur suivante :Bad Material definition in element number 32 instance COHÉSIVE-1: zero or negative initial dilatational modulus caused by bad material data. Please check your material input and any initial conditions if necessary. Est-ce-que vous pouvez m'aider à lancer le job. Merci

@theliviamello

7 жыл бұрын

Hi! I'm facing the same problem. Were you able to figure out how to solve it? Any hint will be appreciated .

@peixunwang6733

7 жыл бұрын

hi, i encounter the same problem, have you solved it? could you give me some advice???

@peixunwang6733

7 жыл бұрын

have you solved it? we can discuss about it!!!

@theliviamello

7 жыл бұрын

I'm writing a VUMAT user subroutine and one of its requirements is to assume the material to be elastic at stepTime=0.0 (you can find a better explanation on Abaqus documentation on the User Subroutine Guide). This is necessary for the data check phase and has to do with the calculation of the stable time increment. I hadn't defined the elastic properties very well at stepTime=0.0 so that is what was causing me problems.

@peixunwang6733

7 жыл бұрын

ok, thanks for your answer!!! best wishes for your life and work!!!

Hello Sanan. May I have your contact detail please? Would like to ask you something related the coh-element(s)? I'll need to sketch it in order to show you. I'm modelling slightly different thing as compared to your tutorial and I couldn't figure it out. Hope you could help.

@SanaanKhan

5 жыл бұрын

Please put your questions here...if have the answer I will reply... others may also join us.

@yongqi914

5 жыл бұрын

@@SanaanKhan Thank you for getting back to me. My question is regarding the cohesive interfaces in masonry structure. i.e. if I have four bricks (top left, top right, bottom left, bottom right). In this case if I define the cohesive interfaces as per your tutorial, I will have an undefined tiny part in the middle, if that make sense?

@SanaanKhan

5 жыл бұрын

for masonry structures the friction is high during delamination. i recommend you to use cohesive surface methodology. it is simple and easy to use with good convergence results. further you can add friction parameter as well.

@yongqi914

5 жыл бұрын

@@SanaanKhan Noted and thank you very much for your advice! xD Do you mean creating part(s) for the cohesive elements? OR defining the cohesive elements as the interactions? I'm gonna try now...

Hi Sanan, I am trying to model ductile damage using abaqus. I have only experimental tensile data. How can I find Stress Triaxiality and fracture strain. If you give me your email I can provide the data file and also the abaqus file.

@SanaanKhan

8 жыл бұрын

+Saimon Islam stress triaxialty is found after rigorous experiments with different specimen gauge dia's. but if ur material is not classified which i think is, then there must be a literature on it. there must be a curve between stress triax and frac strain. go for a relaxed value or input the digitised history data.

Hi Sir, This video much useful to me, Can you send me the PDFcopy of ASTM D7136/D7136M -15, I have 12th edition. This could help me in the final year project

give me your mail

@SanaanKhan

9 жыл бұрын

Please comment below for any suggestions/ query or mail me : er.sanan@gmail.com