Damage initiation and evolution during monotonic cooling of laminated composites

The objective of this work is to develop a methodology to predict matrix damage initiation and evolution in laminated composites subjected to monotonic cooling using discrete damage mechanics and a careful characterization of the required temperature-dependent material properties. Since prediction of thermo-mechanical damage requires precise knowledge of the temperature-dependent properties of the material, back-calculation of fiber and matrix properties from different sources is included. The proposed methodology is flexible, in that it can be adapted to the availability of experimental data. A compilation of literature data is developed to estimate the properties of several fiber and matrix systems. Prediction of lamina and laminate temperature-dependent properties are compared with available data. Furthermore, temperature-dependent fracture toughness of four material systems are estimated from available crack density data. For the material systems studied, it is found that temperature-independent fracture toughness is satisfactory for prediction of damage initiation, evolution, and saturation.