General Mechanical

General Mechanical

Cone indentation – APDL

    • Aurelien
      Subscriber

      Dear all,


      I have to simulate the indentation of a rigid circular cone  into an linear elastic material. The goal is to record the force-displacement curve and repeat the simulation for different cone angles (angle between the generatrix and the cone axis varies from 15 to 65°.


      The input file is already done, here are a few details about the model:



      • 2D axisymmetric simulation

      • Linear elastic material modelled with elements PLANE183

      • Rigid cone modelled with Target elements (TARGE169) and controlled in displacement with Pilot node

      • Contact elements (CONTACT172) are created at the upper part of the based material



      Here is my problem: I cannot reach large penetration depth because of element distortion (see following error message and distorded element).




      In order to solve this issue I tried to:



      • Adjust manually the number of substeps

      • Adjust the mesh refinement


      However it turns out that the maximum penetration I can reach is strongly related to the mesh size: I can only reach large penetrations with large elements - but if I do so I have only a few elements in contact with the cone.


       


      So my last idea was to use nonlinear adaptive meshing (NLAD) with mesh quality based criterion in order to remesh the area around the distorded elements. The remeshing is done with general remeshing (NLESH). However this does not work: the distorded element is detected but the remeshing fails and the simulation continues with the old mesh. Here is the error message:



      My main questions are:



      • Is the adaptive meshing a good solution to solve my problem ?

      • If no what would you suggest to reach large penetration depth ?

      • If yes do you have any idea how to solve the remeshing failure ? NLAD command cannot be reached from the GUI so it´s kind of difficult to debug..


      I´ve been working on this topic for quite a long time and I´m really stuck now. Any help would be greatly appreciated. Please let me know if you need the input script or any more information about the model.


       


      Regards,


      Aurelien

    • jj77
      Subscriber

      Never used nlmesh in apdl - much easier to do in WB (it probably uses the same commands as apdl though).


       


      One example to look at is  - look it up in the help manual:


       


      3.10.4. Example: 2-D Metal Extrusion Simulation


       


      There are other examples also that might be of help.

    • Wenlong
      Ansys Employee

      Here is the link of the 2D metal extrusion simulation jj77 mentioned:


      https://ansyshelp.ansys.com/account/Secured?returnurl=/Views/Secured/corp/v194/ans_nlad/advmnlabenefits.html#advmnacracksim


      You may also try updating the contact stiffness more frequently, reducing the contact normal stiffness and even try different material properties (it is hard for material to keep linear elastic for such large deformation). 


      Bests,


      Wenlong

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