A three-dimensional damage analysis framework for fiber-reinforced composite laminates

Abstract

While fiber-reinforced composites are increasingly applied as structural components due to superiority in lightweight and robust mechanical performance, reliable and efficient numerical assessment is often essential for supporting such applications and can even stand in lieu of testing, yet uncertainties and controversies remain despite continuous efforts over decades. To address the deficiency, a three-dimensional (3D) damage analysis framework based on the method of finite elements (FE) was proposed to predict the initiation and evolution of damage as well as the load-bearing capacity of a laminated composite structure subjected to general loadings. Within the analysis framework, stress interaction and coupling effect were embedded in failure criteria and damage evolution laws. With both geometric nonlinearity and shear nonlinearity accounted for, a smeared constitutive damage model circumventing the longstanding problem of FE mesh dependency was formulated. Built upon the strength theory of fiber kinking, calculation of initial misalignment angle was explicitly determined. Further, to determine the damage variables, stress contributions to energy dissipation during crack initiation and growth were considered. Selected verification studies, including transverse compression and open-hole compression, demonstrated excellent agreement of numerical predictions with existing experimental results. The proposed 3D damage analysis framework can reproduce the expected failure mechanisms, strength, stress distributions and structural load-bearing capacity of fiber-reinforced composite laminates.