nArrayFirst of all, I looked at the Chapter 13 in the ANSYS Help documentation.nnThe notes I followed for the debonding setup from the documentation areIncluding CONTA172nHowever, there is no difference in terms of results if I compare them when I include CONTA172 and do not include it.nnAugmented Lagrangian method or pure penalty method (KEYOPT(2) = 0 or 1)nPure Penalty has been already chosen for formulation criteria.nnBonded contact (KEYOPT(12) = 2, 3, 4, 5, or 6)nHere is the cotact option as Bonded.nnBilinear material model to be includednCan you please tell me how I can include the bilinear models in the mechanical?.nBased on your suggestion, I configred a quite simple models where I used a pair of sheets. I investigated three different cases for which you can see the bondary conditions below.nSheets with physical gaps or without gap showed no difference in terms of results. In addition to that, I am also suspisious about the results when I see the animation for case I) where I applied 0.015mm displacement. You will see that he upper sheet is being buckled in a strange way; it bends upwards along the mid-section.nncase I)nnstrange buckling behaviour)nnanimation for case I)nArraycase II)nnanimation for caseII)nArraycase III)nnanimation for case III)nArraynPlease note that, for all, displayed results are animated in scale 16.nnI also conducted a convergence study on this simple model to figure out the optimum mesh size. In this convergence study, I used more than 150 design points ranging from 5mm to 0.0625mm. Below you will see the graphs for convergence analysis. I was expecting the curves to reach a plateu at a specific mesh size, see Figure 1). However, what I see is that the curves are continuously climbing as shown below in Figure 1) and in Figure 2).nnnFigure 2)nnnFigure 1)nnI would apprecite it if you share your ideas.n