Abstract:
"Copper Tube Compression in Z-Current Geometry, Numerical Simulations and Comparison with Cyclope Experiments"
This paper benchmarks a new electromagnetism module being developed for the LS-DYNA software by simulating the compression of a copper tube in a Z-current geometry. The goal is to create a robust tool for coupled mechanical-thermal-electromagnetic simulations that can accurately model the behavior of metals under large strain at high strain rates. The module solves the Maxwell equations using a Finite Element Method (FEM) for the solid conductors and a Boundary Element Method (BEM) for the surrounding vacuum. Numerical simulations of a copper tube were compared with experimental data from the Cyclope facility. The study investigated the influence of several parameters, including the electromagnetic time step, the choice of constitutive law (Steinberg vs. Johnson-Cook), the inclusion of a thermal solver, and the effect of current diffusion. Results showed that taking into account the diffusion of the current through the volume of the cylinder, as opposed to assuming pure surface conduction, slightly reduces the displacement and improves agreement with experimental data. The thermal solver predicted significant Joule heating, with the outer diameter reaching 400°C.
