Finite element analysis of unidirectional composite elastic constants predictions considering interface

Abstract

Composite elastic constants prediction is an essential issue in composite mechanics. In this paper, a variety of experiments are used to measure the macro elastic constants of composite. Then the macro stiffness predictions of unidirectional composite based on finite element analysis (FEM) are conducted. Through this five independent macro elastic constants of composite (EL - longitudinal modulus, ET - transverse modulus, GLT - in-plane shear modulus, vTT - main Poisson's ratio, VTT - transverse Poisson's ratio) could be obtained. First square and hexagon RVEs considering the effect of interface cohesive zone were established to gain five macro elastic constants. Fiber is transversely isotropic material, and matrix is isotropic material. Finally a RVE of fiber random distribution containing 25 fibers were modeled and all the relative errors are less than 15%. Through finite element analysis, numerical models can effectively verify the experimental results. In future, the amount of tests can be reduced by means of numerical analysis.