A new trigonometric zigzag theory for static analysis of laminated composite and sandwich plates

In this work, a new trigonometric zigzag theory is proposed for the static analysis of laminated composite and sandwich plates. This theory considers shear strain shape function assuming the non-linear distribution of in-plane displacement across the thickness. It satisfies the shear-stress-free boundary conditions at top and bottom surfaces of the plate as well as the continuity of transverse shear stress at the layer interfaces obviating the need of an artificial shear correction factor. An efficient displacement based C0 finite element model is employed for the accurate assessment of the static behavior of laminated composite and sandwich plates. Some numerical examples covering various features such as different material properties, loading and boundary conditions of cross-ply composite and sandwich composite plates are solved. Efficiency and applicability of the present model is ascertained by validating the evaluated results not only with three-dimensional elasticity solutions but also with the available published results based on other shear deformation theories.