Bimodulus composite materials based variable stiffness laminates using curvilinear fibre-reinforced layers- static bending characteristics under mechanical and thermal loadings

Abstract

The present work concerns with the bending analysis of variable stiffness laminates of bimodulus composite materials subjected to mechanical and thermal loads. The variable stiffness over the surface of lamina is formed using tow-steered composite layers i. e. curvilinear fibre paths-based laminae. The composite materials involved in these laminae are assumed exhibiting different sets of material properties depending upon whether the fibre directional strain action is tension or compression. The equilibrium equations are obtained using the minimization of total potential energy principle and they are solved using finite element methodology based on shear flexible theory. The positions of neutral surfaces of the laminate are evaluated iteratively using Newton-Raphson scheme as these surfaces are not known a priori. The formulation shown here is validated against the analytical solutions available in the literature. A systematic investigation assuming geometrical and material parameters like thickness and aspect ratios, material ratio, boundary conditions, lay-up, curvilinear fibre paths, etc. is conducted to reveal the laminate bending characteristics of bimodular variable stiffness composite laminate.