New, Innovative Technologies for EMP/HPM Hardening of Military and Commercial Systems and Equipment

A six-month Phase I project is proposed to demonstrate the feasibility of a hierarchical method for more accurately estimating the material parameters of constitutive models in DYNA3D, thereby enhancing the fidelity of nonlinear finite element models. Thehierarchical approach combines the distinct advantages of coupon, component and system-level testing with Bayesian statistical parameter estimation. Bayesian sequential estimation retains the information gained from previous estimates in a covariancematrix of the estimates, which is updated with test data from each subsequent test. It is also proposed that a one-stage version of the Bayesian estimator be applied to a fragmentation model developed by General Atomics, SAIC and George Mason University.The material representation in the model will be generalized to include stochastically correlated bond strengths between element clusters in an effort to more accurately represent the fragment weight distributions observed in arena tests.The proposedproject will build upon a recently completed SBIR Phase II project also sponsored by DTRA, which developed and implemented methods for nonlinear model validation and verification in a MATLABr Nonlinear Model V&V Toolbox. This toolbox is currentlyundergoing beta-testing at U.S. National Laboratories. The proposed project will extend the toolbox to include a hierarchical method for material parameter estimation. The resulting toolbox should benefit all users of DYNA3D, including the U.S.transportation industry that uses the code extensively for vehicle crash simulations, and the design of roadside safety barriers.