Hi Deepak,

there are two different ways to apply the cohesive properties to the model;

1) Cohesive element

2) Cohesive surface

most of the time, it is necessary to use the zero thickness elements (for example for fatigue crack growth), but how to do this?

after meshing your model (with normal element and cohesive elements) in the Mesh  modulus, choose the "Mesh" from the top toolbar, the Edit mesh window will be appeared. Choose "Node" for category and "Edit" for method.

after that, you have to select the nodes on the both sides of the cohesive layer! and press "Done" on the bellow bar.

The "Edit Nodes" window will be appeared. you can see the location of the selected nodes in the window. select "Coordinates" for the "specification method".

now you have to import the new location of zero thickness cohesive layer. if the cohesive elements layer is horizontal, you have to just edit the "Y" value that is shown with "2" in Abaqus software. inter an average of two given number ((minimum+maximum)/2) in the box in front of "2". 

Also you should deactivate the "Project to geometry" !

after this, you can have the cohesive elements with zero thickness!!!

I hope that you can do this.

Best of Luck ;)

Dear Deepak Kumar

In ABAQUS it is better to use cohesive contact surfaces to model the behavior intrinsic to zero-thickness cohesive elements. However, you could create zero-thickness cohesive elements by editing the mesh and afterwards modifying the corresponding nodal connections in the input file.

I think that most of the people who are working with zero thickness cohesive elements in ABAQUS develop python scripts (or Matlab, Fortran...) to facilitate the process. Since defining zero thickness cohesive elements is not straightforward, and therefore I will recommend you the use of contact surfaces with cohesive behavior. 

Best regards

Hello,

In your case, you should write a program to insert the cohesive elements in all the interelement boundaries. You don't have to use other constraints like tie, since the cohesive elements share the nodes with the solid elements, your meshed piece is still continue from the mechanic point of view. But you should pay attention to the numbering of nodes for the cohesive elements. If you are not very familiar with Abaqus, I suggest to you to do it carefourly and to begin with consulting the documentation of Abaqus concerning the cohesive elements. Anyway, it is feasible, you can use matlab to program, for example. Hope that helps you.

Best regards,

Thanks for your valuable advice.Is it necessary to write programme? As i know ,In abaqus,we can embeds  solid cohesive element directly with some thickness with shared nodes option.

If you have some example programme for 3-d cohesive element,Then can you share with me.

Once again ..thanks.

Hello,

If you just need to insert a few cohesive elements but not everywhere between all the solid elements, you can do it in Abaqus cae. But I don't think that is your case.

I don't have such programs. Just  in the litterature, there are some authors who have written such preblems, but I don't think that they would share them.

Hello,

I have mistaken, you can exactly resolve your problem of delamination in Abaqus CAE. I guess you need a layer straight with none thickness.

To do the insertion in Abaqus CAE, you should first create a layer (with a certain thickness) for the cohesive behavior material properties, and then you mesh this layer with cohesive elements. After meshing totally your part, you should go to Mesh-->Edit mesh-->Node-->Edit-->Choose all the cohesive elements-->tragg on Coordianates-->Enter the values to make the thickness of the layer zero. But, beforehand, you should mesh the layer using the sweep method in order to garantee the correct numbering of nodes for the cohesive elements.

Good luck.

Hi Deepak,

there are two different ways to apply the cohesive properties to the model;

1) Cohesive element

2) Cohesive surface

most of the time, it is necessary to use the zero thickness elements (for example for fatigue crack growth), but how to do this?

after meshing your model (with normal element and cohesive elements) in the Mesh  modulus, choose the "Mesh" from the top toolbar, the Edit mesh window will be appeared. Choose "Node" for category and "Edit" for method.

after that, you have to select the nodes on the both sides of the cohesive layer! and press "Done" on the bellow bar.

The "Edit Nodes" window will be appeared. you can see the location of the selected nodes in the window. select "Coordinates" for the "specification method".

now you have to import the new location of zero thickness cohesive layer. if the cohesive elements layer is horizontal, you have to just edit the "Y" value that is shown with "2" in Abaqus software. inter an average of two given number ((minimum+maximum)/2) in the box in front of "2". 

Also you should deactivate the "Project to geometry" !

after this, you can have the cohesive elements with zero thickness!!!

I hope that you can do this.

Best of Luck ;)

Hi,

If I use a cohesive contact approach to define contact between 2 materials, is there a way in which I can define failure strength for the cohesive contact?

Hello Sharanya,

    You can define  interaction properties as cohesive behavior..then define damage..choose failure criterion for cohesive element....you can define damage evolution also based on displacement or energy .

Hope this will help you.

Hi,

I have two questions

   1.  How to create cohesive elements (with definite thickness) sharing nodes with other elements . 

2.  can i give the damage properties for cohesive elements (with definite thickness) through interaction properties or is there any other procedure???

Hi Anush,

        You can create cohesive elements with finite thickness in two ways:1) by creating orphan mesh and inserting the finite thickness of cohesive element. In this method ,you have to modify the co-ordinate of cohesive element. 2). by creating geometry of finite thickness in your model and with fine meshing in that region with assigned cohesive element.

for your second question, there is two method 1). cohesive element 2). cohesive surface...if you want to use cohesive element method , then you have to give damage properties in Material properties with traction separation law. 2) In this method you can use surface interaction as cohesive behavior.

You want to know in details..you should refer abaqus documentation (abaqus  CAE user manual 6.10)

section 20  Adhesive joints and bonded interfaces.

Hope this will help you.

Hi Deepak,

                     Thanks for your valuable advice. I have one more doubt in connecting cohesive elements to surrounding material.

I have to model shearing of  two blocks with one block fixed to ground , the interface between these two blocks is the cohesive element(with definite thickness). I have tied the cohesive elements with the fixed block , so what should i do on the other side plz suggest

Try to tie other side also..and see the effect...

Hi deepak, your idea worked out well thanks. Now i have gt struck up at another point

In Abaqus,Static riks analysis- I have to do tensile test on a composite with cohesive interface.

1. a)Input -  Total Arc length is 0.5 , b)0.001as initial increment ,c)no of increments 500

2. Output: No errors arise from the output but in  output the total arc length is 9.23e-2 and what may be the reason for this??

 Hello. I have a question about the procedure to connect the 3D cohesive element layer to other components. Should I edit the mesh to get zero-thickness layer before the assembly or after that?

Thank you.

Hi

I have a related question. I have to define a 0.05 mm thick cohesive layer in between concrete slab and steel beam flange. I have defined a different part of cohesive element of 0.05 mm thickness. 

during declaring material properties I have followed mechanical-elasticity-elastic-traction since i want to use uncoupled traction type. 

the problem is that I want to know what does it mean E/Enn ? Des it mean Knn and what does it mmean G1/Ess does it mean Kss

Manik, you can find out the answer of your question under Cohesive elements in abaqus documentation 

Hello,

I was going through the thoughts posted under this question and I was wondering if anyone would be able to answer a query that I have regarding modeling cohesive elements! I am trying to connect a vertical cohesive plane with horizontal plane. Imagine two planes crossing at right angles! Now if I apply concentrated fluid load at one end since I am using cohesive pore pressure elements then, it should be able to transfer fluid everywhere in the said crossing geometry.

Thanks,

Aditya

Hello Everyone,

Please provide any suggestions or thoughts on question asked in my previous comment! ANY thought/suggestion might be helpful as. I am really stuck at this point!

Thanks & Regards,

Aditya Nikam

Hi everyone i think youtube website is the best tool for learning about Cohesive element . but i should notice that the method of defining this element in explicit analysis and implicit analysis is different . firs you should know the analysis method

Hello

I want to apply cohesive surface interaction between the clay bricks to develop masonry wall in baqus explicit. Is there any shorter method to apply cohesive surface to all the bricks without selecting the bricks surfaces individually??

Thanks

Hello

I need to model the interface between geosynthetic material and asphalt. I am using cohesive elements. I have created zero thickness cohesive elements. My doubt is, what is the best method to connect these cohesive elements to the solid elements of asphalt?? 

Thanks

Hi Nitin

Yes. You can use abaqus "find contac pair" feature unless you are dealing with a 2D problem.

Best,