- 2014, CISM, Udine. Composite materials, and heterogeneous bodies in general, develop internal damage under imposed thermomechanical loading that can evolve to critical states of failure by a complex set of mechanisms. A hierarchical multiscale modeling approach to treat this behavior is generally not adequate. Instead, a synergistic approach is proposed that combines a continuum framework for macroscopic constitutive response and judiciously selected micro-level analyses of governing local failure mechanisms. Explicit characterization of physically observed features of micro-level failure is done by second order tensors that enter in the macro-level framework as internal variables. The approach is illustrated on damage of composite laminates made by stacking unidirectional fiber-reinforced layers.