Cohesive Element Modelling

Altair Forum User
Altair Forum User
Altair Employee
edited October 2020 in Community Q&A

Hello, I been trying to model delamination using cohesive elements on hypermesh for LS-Dyna code. I am unable to model cohesive elements. I downloaded some k files from LS-Dyna support website in which a double cantilever beam test is performed using cohesive elements. However, I have not been able to replicate the cohesive elements in my models. If any one has any experience in cohesive element modelling please tell me how to do this. Thanks

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Answers

  • Rahul Rajan_21763
    Rahul Rajan_21763 New Altair Community Member
    edited June 2015

     Hi,  HyperMesh- Dyna user profile supports  cohesive zone elements with ELFORM 19/20.

     Element connectivity of a cohesive element: 

     There are two element formulations in LS-DYNA, which can be used with cohesive material models: ELFORM 19/20. ELFORM 20 will transfer moments between the bonded parts, whereas ELFORM 19 will not.

      The order of the nodes in defining the element is important. If the cohesive element bonds Element A to Element B, nodes 1-2-3-4  of the cohesive element should be shared by  Element A or by Element B.  In the first case, the normal of face 1-2-3-4 should point towards Element B and nodes 5-6-7-8 should be shared by Element B. In the second case, the normal of face 1-2-3-4 should point towards Element A and nodes 5-6-7-8 should be shared by Element A. 

     As for assigning the elform card image, that is done on the *SECTION_SOLID card image.   Regards  Rahul R