Micromechanical modeling of composites with mechanical interface – Part II: Damage mechanics assessment

Continuing the work initiated in the Part I [Bonora N, Ruggiero A. Micromechanical modeling of composites with mechanical interface – Part I: unit cell model development and anufacturing process effects. Compos Sci Technol 2003], in this paper the possibility to account for different damage mechanisms, in the unit cell model (UCM), explicitly developed for composites with mechanical interface, is discussed and results for Ti-15-3/SCS-6 composite laminates are presented. Starting from the analysis of the constituent behaviors a probabilistic model based on Weibull statistics is developed for fiber failure, while a ductile damage model which incorporates stress triaxiality effect has been used for predicting metal matrix progressive failure. Fiber–matrix debonding process has been naturally predicted incorporating the material manufacturing process in the stress/strain history. Numerical results performed with the UCM applied to 0° and 90° unidirectional laminates, loaded both in tension and compression, have been compared with experimental results at both macro- and microscopic scale.