Rank deficiency in superconvergent patch recovery techniques with 4‐node quadrilateral elements

Abstract

SUMMARYThe linear systems of equations generated by the Superconvergent Patch Recovery technique (Int. J. Numer. Methods Eng. 1992; 33:1331-1382; Comput. Methods Appl. Mech. Eng. 1992; 101:207-224) can exhibit rank deficiency under certain purely geometric conditions. The rank deficiency problem can be corrected simply and efficiently by utilizing a local rotated co-ordinate system. This rotated SPR procedure is easily automated and adds robustness to automatic adaptive solution methods.