General Mechanical

General Mechanical

Solver pivot warning in 3-point bending model

Tagged: ,

    • jinglun
      Subscriber

      I am simulating a 1/4 model of a 3-point bending test, with symmetry regions applied. The sample is a shell from ACP while the crosshead and support are solids. The shell offset is set to "Top". The crosshead presses down on the sample along the Z axis. All contacts are frictionless, and "closed". The model worked fine when ACP was not used, everything else being the same (the sample was a simple midsurface shell). But with ACP I get many solver pivot warnings, with UX, UY, UZ of node 483 (highlighted in figure) repeatedly mentioned.


      Note that in previous runs I used either all solid bodies, or all shell bodies. Here I have both solids and a shell body.


    • jinglun
      Subscriber
      Heres the link to the project archive: nhttps://entuedu-my.sharepoint.com/:u:/g/personal/angj0054_e_ntu_edu_sg/EWmROcGhMBxBo2RTBP4c9I8BLk_pL8SfTd2uJKYT7eSJRA?e=eqKi84n
    • SaiD
      Ansys Employee
      Hi,nI see a gap between the sample and lower support, so that might lead to some initial rigid body motion before contact is established. I am not sure why the contact status is reported as closed when visually we can see a gap there. May be I am missing something? If the issue is rigid body motion at contact regions, you can use contact stabilization damping.nYou are right about about the symmetry part. It is possible that the general rigid body motion results in a very high displacement at node 483. It need not mean that the issue is specifically at that node. nDue to company policies, we cannot download attachments. If you have any additional questions, please insert images as you did in your first post.nnHope this helps,nSai
Viewing 2 reply threads
  • You must be logged in to reply to this topic.