Contact mesh and penalty method approaches applied to a severe contact problem

This work aims to propose a comparison between the well known penalty method and the contact mesh approach in an Explicit Finite Element Method applied to a severe contact simulation. The contact mesh links the probable contact regions and minimizes the potential error. In this approach, the algorithm shrinks the whole model in the same proportion, searches for the nodes which will probably start contact in the next iterations, creates the contact mesh and transfers the conditions when the distance would be enough to start the contact without the shrinkage. After the simulation finishes, the whole model returns to its normal size to correct visualization. In order to test the method efficiency and guarantee a reliable comparison, a microindentation experiment that represents a severe contact problem was simulated using explicit integration for both contact approaches. As results, both methods showed similar good results when compared to experimental tests for large deformations and to observe the overall behavior. In the case of small deformations and to observe the local behavior of small contact areas, the penalty method presents instabilities variations that are close in size to the real deformations, different from the contact mesh approach, which shows smooth transition between the mesh nodes, similar to the experimental results