Integrated experimental-numerical characterization of geological materials under shock and impact

Scientific investigation of transient processes and engineering design of structures for dynamic loading conditions are still a great challenge. Other than quasi-static loading conditions a dynamic application of loads by impact or blast leads to additional effects that enhance the complexity of the thermo-mechanical material behavior. They can be reduced to two basic phenomena: first, the strain rate dependent change of mechanical behavior and, secondly, the evolution and propagation of shock waves. In order to understand the structural behavior under transient loading conditions, the involved materials need to be characterized by material tests. Mathematical formulations are needed for the description of both the strain rate dependent deviatoric behavior and the non-linear Equation of State responsible for the shock wave formation. Implemented into numerical codes these constitutive equations allow for a predictive simulation of the structural behavior. Sometimes numerical simulation itself can be used to derive material properties. This is the case when for example the material is composed of two or more constituents for which the individual thermo-mechanical properties are known. Modeling the composite material as specimens and application of loads that may be outside the load types applicable in experiments leads to additional results not achievable in a pure experimental approach. Therefore, an integrated experimental-numerical approach for the characterization of materials under transient loading conditions is more and more preferred if predictive capabilities are needed for the highly complex phenomena observed in the related structural applications of interest.