Interlaminar stress mixed finite element analysis of unsymmetrically laminated composite plates

An interlaminar stress mixed finite element method based on the local high-order lamination theory is presented. The nodal unknowns in this C⁰ isoparametric element are three displacements, three rotations, and five higher-order functions as the generalized degrees of freedom in the mid-surface of each layer and three interlaminar stress functions as the generalized degrees of freedom at the interface between the layers. The interlaminar stresses at the interface can then be accurately determined. The unsymmetrically laminated composite plates, which are fully simply supported, subjected to a sinusoidal distribution of transverse load are examined in order to validate the present interlaminar stress mixed finite element. The finite element results presented here are compared with the three-dimensional elasticity solutions and other finite element solutions based on global high-order lamination theories.