My research goal is to reliably predict damage in inelastically deforming structural materials. Damage refers to a variety of phenomena including functional fatigue and fatigue failure. This goal is achieved through two efforts. The first effort is to develop microstructure-sensitive models for damage in metals using an effort combining theoretical and empirical components. The second effort is to quantify the uncertainty in these models. Predictive models for damage together with a quantification of their uncertainty provide a robust tool for component design using these structural materials.
Deformation response of metals can be complex due to the presence of multiple deformation modes - slip, phase transformation, twinning and other aspects like interaction between the grains, anisotropic mechanical properties and complex loading paths. Microstructural modeling can elucidate the fundamental phenomena defining deformation patterns. Macro scale modeling can provide fast and robust tools to aid in component design process while accounting for the complex deformation mechanisms. Modeling of various inelastic deformation modes can contribute to reliable prediction of damage.
Synchrotron X-ray diffraction based techniques can quantify deformation and microstructure of metals at multiple length scales. E.g. μXRD can reveal intragranular orientation spread and strains, HEDM can provide grain-scale statistics of orientation and lattice strains and powder diffraction can provide component-scale texture and strains. DIC can provide surface distribution of strains during a deformation test. These techniques together are ideal to inform and validate multi-scale numerical models for damage.