A direct modification method for strains due to non-conforming modes

This paper addresses an efficient modification method that eliminates the undesirable effects ofstrains due to various non-conforming modes so that the non-conforming element can pass the patch testunconditionally. The scheme is incorporated in the element formulation to establish new types of non-conforminghexahedral elements designated as NHx and NVHx for the regular element and variable nodeelement, respectively. Non-conforming displacement modes are selectively added to the ordinary(conforming) element displacement assumptions to improve the bending behavior of the distorted solidelement. To verify the validation of proposed direct modification method and the improvement of elementbehavior, several numerical tests are carried out. Test results show that the proposed method is effectiveand its applications to non-conforming solid elements guarantee for the element to pass the patch test.