Layered finite element analysis of laminated composite plates by using unsymmetric membrane element and non-conforming bending element

This study presents a new quadrilateral element for layered finite element analysis of laminated composite plates which is obtained through assemblage of membrane and plate bending elements. The membrane component is a new unsymmetric quadrilateral element with drilling degrees of freedom, in which two different types of displacement fields are used as the test and trial functions. The test function is a new kind of displacement field with drilling degrees of freedom obtained by using interpolation along the element edges. The trial function is a stress field computed through analytical solutions of Airy stress function. The bending component of lroposed element is a non-conforming plate element that its displacement is computed using third-order deformation modes and the rotational field of element is defined by using first-order Jacobean matrix. The results of numerical benchmark problems show that the the proposed element is capable for analysis of laminated composite plates with varius geometry and boundary. The maximum error of the proposed element among the considered numerical problems is only 1.5 percent.