Thermoelastic constants of symmetric laminates with cracks in 90-layer: application of simple models

Abstract

The change of thermoelastic properties of cross-ply and quasi-isotropic laminates with intralaminar cracks in layers is analysed. Predictions are performed using previously derived general expressions for stiffness of symmetric damaged laminates as dependent on crack density and crack face opening and sliding. It is shown that the average crack opening displacement can be linked with the average value of axial stress perturbation between two cracks. Using this relationship, analytical shear lag and Hashin's models, developed for axial modulus, can be applied for calculating thermal expansion coefficients, in-plane moduli and Poisson's ratios of damaged laminates. The approach is evaluated using finite element method and it is shown that the accuracy is rather similar to that in axial modulus calculation.