Assessment of the refined sinus model for the non-linear analysis of composite beams

The objective of this paper is to evaluate a new three-noded mechanical beam finite element for the non-linear analysis of laminated beams. It is based on a sinus distribution with layer refinement. The transverse shear strain is obtained by using a cosine function avoiding the use of shear correction factors. This kinematic accounts for the interlaminar continuity conditions on the interfaces between layers, and the boundary conditions on the upper and lower surfaces of the beam. A conforming FE approach is carried out using Lagrange and Hermite interpolations. It is important to notice that the number of unknowns is independent from the number of layers. Buckling, post-buckling, and non-linear bending tests are presented in order to compare with the ones available in the literature or based on a 2D analysis. The influence of mesh, boundary conditions, length-to-thickness ratios and lay-ups is studied to show the accuracy and the efficiency of this finite element.