Internal failure assessment of laminated plates via surface data inversion

Abstract

Abstract This paper addresses the challenge of directly measuring internal stresses and failure states in carbon fiber composite laminates. It proposes a failure assessment method that combines Tsai-Wu criteria with stress inversion based on measured surface strains. Surface strains are obtained through strain gauge tests. Internal principal strains in each layer are calculated using layup angles and strain coordination relationships. Single-layer two-dimensional stiffness matrices are employed to compute principal material stresses for each ply. Abaqus finite element analysis provides comparative validation, with experimental and simulated stress results showing less than 10 % error. The method’s validity was further validated through non-destructive testing and loading experiments, with the maximum relative error between theoretically predicted failure load and actual results being 8.1 %. This approach provides a practical pathway for structural safety assessment and design optimization of carbon fiber laminate structures.