A novel hybrid finite element model for modeling anisotropic composites

In this paper we proposed a novel hybrid Trefffz-type finite element method to simulate mechanical behavior of anisotropic composite materials based on its associated Green's functions. The hybrid method is formulated based on two independent assumptions: intra-element field covering the element domain and inter-element frame field along the element boundary. A modified functional, which satisfies the governing equation, boundary and continuity conditions between elements, is proposed to derive the element stiffness equation. In this work, the foundational solutions of anisotropic materials in terms of the elegant and powerful Stroh formalism are employed to approximate the intra-element displacement field of the elements, while the polynomial shape functions used in traditional FEM are utilized to interpolate the frame field. Several numerical examples are presented to demonstrate the performance of the new method by comparing with the analytical or numerical results from literatures and ABAQUS. Numerical results show that the proposed method is accurate and efficient in modeling anisotropic composites materials in contrast to traditional FEM, and it is potential to be further extended to analyze composite laminates easily.

► Only boundary integrals are involved in element stiffness equation.
► High accuracy for anisotropic materials.
► Stroh formalism is first employed in finite element model.
► Deal with isotropic and anisotropic materials using one finite element model.