Modeling framework for free edge effects in laminates under thermo-mechanical loading

In this paper, a novel Quasi-2D (Q-2D) plane strain formulation for predicting interlaminar stresses in multi-directional laminates is developed and implemented within the finite element method framework. In particular, analyses of free edge stresses in composite laminates subjected to uniform axial and/or thermal loading are conducted. The Q-2D modeling approach presented here is validated by comparing the predicted interlaminar stresses with corresponding 3D models and previously published data. Computational time required for determining the interlaminar stresses using Q-2D model is approximately 30 times lower than the 3D analysis of the same laminate. Also, the Q-2D model is implemented within a commercially available software by modifying a 3D model to behave like a 2D model. This is particularly advantageous over developing an in-house finite element method code to capture the complex free edge stress states in multi-directional composites. Hence, the current framework can potentially be used as a computational tool for efficiently predicting the interlaminar stresses in different laminates subjected to thermo-mechanical loading, which can assist in determining interlaminar regions susceptible to free edge delamination.