I am trying to establish contact between two newly generated surface after failure in Implicit. For example, i have applied enough tensile force to break the part into two pieces and then compressed two piece to examine is there any contact between the newly generated surfaces. As you can see surfaces simply penetrate into each other without any resistance even though i have defined a general contact with All*self contact domain. Is there any way to be able to define contact in this condition? Your help is highly appreciated.
I am not sure how do you do it in FEM platform. Experimentally, however, the contact forces can be measured accurately. Crack faces coming into contact thereby effectively reducing the crack tip driving forces is a common problem with fatigue cracks. I said fatigue cracks because during load reversals the chances of crack faces coming into contact is more.Why fracture surfaces due tensile load should make a contact at all? I do not understand the relevance of your problem? Nevertheless, I would suggest you to refer ASTM E 647 standard, particularly the Annexure X2. This standard deals with evaluating the fatigue crack growth behaviour of materials. A procedure for evaluating the force due to crack tip contact (called crack closure load/crack opening load) has been described. Pick up the standard that is published after the year 2000. This annex has been introduced after that. Hope this help.
All with self contact does not consider the newly created surfaces (or rather meshed elements forming new surfaces). To get around this you have to select all internal elements in 'slave' surface definition that should consist of all faces of elements - not only outer ones. This can be done by modifying your input deck. See Abaqus keyword ref manual for 'Surface' definition.
Thanks Vaibhav. So you mean i have to use general contact or surface to surface contact? Moreover as there is only one part in the simulation, is it possible to define both master and slave surface with the same part? Your help is highly appreciated.
I used a trick to solve this problem. In order to study the contact of a newly born surface after failure with an analytically rigid plate, I created two steps. First step includes applying tensile force till the specimen fails. In the next step I activated the rigid plate and applied compressive force on plate to flatten the failure interface. I defined a node based surface on the interface of failed elements and defined surface-to-surface contact with rigid plate and node based surface. Node based surface is defined by checking the results of first step to find out which nodes are located on the interface. Now the problem is that although some normal force is transmitted through the rigid plate to the failed specimen, there is big penetration between node based surface and rigid pate. It seems that the interaction does not work properly. I am using 'hard contact' with finite sliding and kinematic constraint enforcement method in surface-to-surface contact. Does anybody have any idea why it's so?
Thanks
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