Electro-thermal-mechanical validation experiments

The design of high-performance magnetic flux compression generators and electromagnetic launchers is dependent upon intimate knowledge of the interaction between electromagnetics and solid-thermal mechanics. A coupled 3D electro-thermal-mechanical (ETM) simulation self-consistently solves equations of electromagnetics (primarily magnetostatics and diffusion), heat transfer (primarily conduction), and nonlinear mechanics (primarily elastic-plastic deformation and contact with friction). ALE3D is a heavily used Arbitrary-Lagrangian-Eulerian hydrodynamics code with a recently added electromagnetics simulation capability enabling the simulation, design, and optimization of ETM systems. Diablo is a relatively new ASC-class parallel coupled multi-mechanics code built from the legacy technology contained within the well-known LLNL-produced codes DYNA3D, NIKE3D, and TOPAZ3D. The coaxial validation experiment test fixture was developed to provide high-quality experimental data from a controlled environment undergoing large magnetically-induced deformations. This experimental data is particularly useful for the validation of coupling between J x B forces and momentum equations in ALE3D and Diablo. This paper discusses experiments conducted for the validation of recently enhanced electro-thermal-mechanical simulation capabilities at LLNL. The 1 MA coaxial test stand was designed with an interchangeable center conductor to serve as a test piece for flexibility in axisymmetric and non-axisymmetric experiment design.