Exact integration scheme for six-node wedge element mass matrix
  Currently, mass matrices are computed by means of sufficiently accurate numerical integration schemes. Two-point and nine-point (Gauss) quadrature remain frequently used. We derive an exact, easy to implement integration rule for six-node wedge element mass matrices based on seven points only. Both consistent and lumped mass matrices have been considered. New metric (jacobian determinant) interpolation accompanied by analytical integration permits computing effort reduction next to accuracy increase of integration rule. In addition, one and four point mass matrices integration schemes have been proposed. Accuracy superiority over equivalent schemes is established. 
Eli Hanukah
math.NA