Goal of this research project is the implementation in the open source finite element code OpenRadioss of novel Surface-To-Surface (STS) contact formulations based on covariant descriptions and local enrichment techniques of the contact boundary. The numerical code employs an explicit dynamics computational framework which imposes challenges in the derivation of suitable frictionless and frictional 3D contact formulations. Efficiency of the contact formulation is of major interest due to the very high number of timesteps required in computational explicit dynamics problems involving large deformations (e. g. crashworthiness analysis).
Low-order finite element approximations can injure the robustness of STS formulations due to the jumping directions of normal and tangential vectors over element boundaries or physical edges. A further goal is the development as well as the implementation in OpenRadioss of novel techniques to increase the smoothness of the contact surfaces. These techniques will be based on the enrichment of the shape functions of the contact surfaces with high order approximations. A main feature of this approach is the strong local character of the performed enrichment, which allows the increase of the smoothness on the contact boundary while ensuring at the same time that the rest of the discretization remains unchanged. The surface enrichment will be based on smooth NURBS descriptions. In order to take advantage of the new smooth contact surfaces a refinement of the frictional contact formulation will be performed.
All the above derivations and implementations will be assessed with regard to their overall performance and efficiency within an HPC framework. Several benchmark problems from the field of explicit dynamics (crash analysis, high speed impact simulations etc.) will be computed with OpenRadioss employing the implementations performed within the research project. These computations will be conducted on the High-Performance Cluster of the Laboratory of Engineering Informatics, which belongs to the Chair of Structural Analysis of UniBw M.
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