Stochastic modeling of the mechanical behavior and reliability of brittle or moderately damage-tolerant materials

Structural materials often have variations in their microstructures and, in some cases, the material properties that derive from microstructure. Thus, it would be reasonable to utilize a statistical approach that considers the effect of these variations. In materials that accumulate some damage before failure, material properties may depend on slight variations in microstructure as these can have significant effect on stress singularities. Therefore, it would be useful to adopt a tool able to account for the microstructural effects on the global response. To this aim, a statistical approach for brittle fracture is used in conjunction with a microstructural-based finite element model, OOF. This computational tool, that operates directly on microstructural images, is employed to investigate the effect of microstructural features on the mechanical behavior of several typologies of complex materials. Computer simulations are performed to analyze the reliability and damage accumulation of laminated microstructures, random polycrystals and particulate composites. Moreover, FGMs (Functionally graded materials) are considered in order to investigate the effect of microstructure variations through thickness on the fracture behavior.