Explicit eight-noded quadrilateral elements

摘要

Conditions under which it is possible to determine exact integrals for stiffness matrix entries for an eight-noded isoparametric plane strain element are investigated. Considerable use has been made of the algebraic manipulation language MAPLE in obtaining the results. For the eight-noded quadrilateral the determinant of the Jacobian is a complete cubic plus a single quartic term. Exact integration of the stiffness matrices can be performed when the determinant of the Jacobian becomes a single linear factor or a product of linear factors.