Contact on internal faces of the structure

sonalipatel

Hello everyone,

I am trying to perform non linear quasi static analysis on the truss problem shown in figure. The constraint is applied on bottom side and compression load is applied on top surface. I am using hyperworks 2019 version optistruct as a solver. Due to compression load, various ligament come into contact with each other and get penetrated. I want to create contact on internal surface of the structure to prevent it. I tried some options but didn't work. I will be really grateful for your kind help.

Note: all the element are 3d brick element created by 'solid map-line drag'. Applied load is 10000 N in -y direction.

<?xml version="1.0" encoding="UTF-8"?>

Unable to find an attachment - read this blog

yuhaohe

There are few things you need to change:

1. You current load step is linear static. Contact is a nonlinear behavior and you need to use nonlinear static load step.

2. You can define contact pairs between the surfaces that will touch each other.

3. The ligament buckles, which is a geometric nonlinearity. You need to use large displacement (LGDISP) analysis.

4. You only have two layers of solid elements through the thickness, which may not have the most accurate bending behavior. 3-5 layers are recommended.

 

You may see an example here. The problem is different, but all the required techniques are the same.

https://2020.help.altair.com/2020/hwsolvers/os/topics/solvers/os/nonlinear_static_analysis_snap_fit_using_continuous_sliding_os_example_r.htm#model-files

 

You may also consider OptiStruct explicit or Radioss, as this problem is quite nonlinear and some experience is needed to debug the model and make it converge in an implicit solver.