PREDICTING FINITE ELEMENT SUBMODEL BOUNDARY CONDITIONS FOR CONTACT MODELS USING RICHARDSON EXTRAPOLATION

This paper considers an efficient way to apply submodeling methods to finite element models using Richardson Extrapolation. A problem is considered where a rigid cylindrical indenter contacts an elastic half plane (RCEHP). A submodeling method is introduced where the errors of the displacements on the boundaries of the submodel are controlled by employing a best-fit Richardson Extrapolation curve. Specifically, the curve is fit to the convergence relationship of various estimates of submodel boundary displacements. The method is tested on the RCEHP problem, and the results of the model predictions for maximum contact pressure are compared to an analytical and converged global model result. The submodeling method predicted the maximum contact pressure of the RCEHP contact interface to be about 7% higher than the analytical prediction and 5% higher than the converged global model prediction. The error is likely due to the selection of the global and submodel domains, the numerical algorithm used to estimate the Richardson Extrapolation Curve Fits, and the mesh refinements used for the various models. The proposed method solved in about 42.6 minutes while the converged global model solved in 11.19 hours. Future work will aim to provide best practices to reduce error and maximize computational time savings when using the method.