Finite element analysis of stiffened and un-stiffened laminated composite plates and experimental verification

FRP laminates have the special characteristics of high ratio of elastic modulus to shear modulus (i.e. 20 < E/G < 50) compared to that for isotropic case ( 0 < E/G < 3) Shear stiffness of these materials is very small compared to their membrane and bending stiffnesses. As a result, shear deflection plays a pronounced role in the gross behavior of laminated composite structures. This paper presents an overview of the higher order shear deformation theory developed for the analysis of stiffened and un-stiffened laminated composite plates. While there exist large number of analytical prediction theories, there is limited experimental validation of some of the analytical method developed. Tests were carried out to verify the analytical model experimentally. Some of the critical observations made during the experimental phase are reported and discussed.