Print Email Facebook Twitter A fast nonlinear conjugate gradient based method for 3D frictional contact problems Title A fast nonlinear conjugate gradient based method for 3D frictional contact problems Author Zhao, J. Vollebregt, E.A.H. Oosterlee, C.W. Faculty Electrical Engineering, Mathematics and Computer Science Department Delft Institute of Applied Mathematics Date 2014-03-31 Abstract This paper presents a fast numerical solver for a nonlinear constrained optimization problem, arising from a 3D frictional contact problem. It incorporates an active set strategy with a nonlinear conjugate gradient method. One novelty is to consider the tractions of each slip element in a polar coordinate system, and use azimuth angles as variables, instead of conventional traction variables. A corresponding preconditioner using diagonal scaling is incorporated. The fast Fourier transform (FFT) technique accelerates all matrix-vector products encountered, due to a Toeplitz structure. Numerical tests show that this method is robust and it significantly reduces the computational time, compared to existing solvers. Subject frictional contact problemazimuth angle variablesactive set strategynonlinear conjugate gradientpreconditionerfast Fourier transform To reference this document use: http://resolver.tudelft.nl/uuid:03cceb66-a5d1-487a-9f96-fc976be07437 Publisher Delft University of Technology, Faculty of Electrical Engineering, Mathematics and Computer Science, Delft Institute of Applied Mathematics ISSN 1389-6520 Source Reports of the Delft Institute of Applied Mathematics, 14-02 Part of collection Institutional Repository Document type report Rights (c)2014 Zhao, J., Vollebregt, E.A.H., Oosterlee, C.W. Files PDF 14-02_Jing_Zhao_tech_rept.pdf 431.3 KB Close viewer /islandora/object/uuid:03cceb66-a5d1-487a-9f96-fc976be07437/datastream/OBJ/view