I have faced convergence problem about self piercing rivet separation of composite and aluminum plate. Composite and aluminum plate dimensions are 150 mm x 35 mm both. Rivet diameter is 8 mm. I have experimental data and setup. According to experimental setup, I have given fixed support and displacement in my 3D geometry in Ansys. I have created composite plate using ACP (Pre) and collect solid model to import in static structural. As in ACP (Pre), I didn't get any symmetry option, so I used complete model for analysis.
There have 3 contact point in my model.
1. Aluminum plate to Rivet
2. Composite plate to Rivet
3. Aluminum plate to composite plate
I have used frictional contact with friction co-efficient 0.2 for these three contacts. Initial contact information shows all contacts are close. According to experimental analysis, after getting around 130 mm displacement between aluminum and composite plate, the SPR joint separates completely. But in Ansys after getting 54 mm displacement, there creates convergence problem. According to Newton-Raphson Residual Force, there shows problem is in "Aluminum plate to Rivet" contact points. I have tried to make mesh fine. I have tried to make element smaller in contact point. I have reduced contact stiffness. I have tried several ways, but I didn't understand what I have to do to solve this problem. In file0.err, there has no better information which can help to solve the problem. In Solver output option before creating convergence problem there repeatedly shows "There is too much penetration at (.........) contact points of the 3D contact elements".
I have attached several images of my Ansys setup and also experimental setup image for better understanding my problem. I have expected a better suggestion to solve my problem from experts of student community forum.
*****Experimental setup during SPR joint separation:
*******All setup in Ansys.
***As displacement and fixed support is given on 25 mm distance from edge of composite and aluminum plate in experimental setup, so I cut these 25 mm from 3D geometry and add displacement & fixed support at the edge. I give displacement in three steps. 1st step 60 mm, 2nd step 100 mm and third step 130 mm.
****Cross-sectional view at the middle from width of 3D model.
*****Aluminum to Rivet contact setup information******
****Force convergence graph before convergence problem occurred.
****Newton-Raphson Residual force which shows problem in Aluminum to rivet contact point.
****File0.err shows these messages.