Matrix cracking evolution in open-hole laminates subjected to thermo-mechanical loads

In this work, a constitutive model is developed and used to predict matrix cracking and fiber damage evolution in all the plies of symmetric laminates when both mechanic and thermal loads are applied. A model previously developed is modified to take into account the thermal stresses that appear in each ply when the temperature is reduced below the Stress Free Temperature. Data of matrix damage initiation and evolution due to thermomechanical loads for four materials and six laminate lay-ups taken from the scientific literature are used to validate the model. A good correlation between the predictions and the experimental results is found. The model is used to analyze the thermomechanical damage in laminates containing a centered hole subjected to in-plane tensile loads. It is observed that the thermal load alone does not produce a stress concentration around the hole but the thermal residual stress accelerates damage accumulation during mechanical load.