A methodology to validate 3D arbitrary Lagrangian Eulerian codes with applications to ALEGRA

In this study we provided an experimental test bed for validating features of the Arbitrary Lagrangian Eulerian Grid for Research Applications (ALEGRA ) code over a broad range of strain rates with overlapping diagnostics that encompass the multiple responses. A unique feature of the ALEGRA code is t hat it allows simultaneous computational treatment, within one code, of a w ide range of strain-rates varying from hydrodynamic to structural condition s. This range encompasses strain rates characteristic of shock-wave propaga tion (10(7)/s) and those characteristics of structural response (10(2)/s). Most previous code validation experimental studies, however, have been rest ricted to simulating or investigating a single strain-rate regime. What is new and different in this investigation is that we have performed well-cont rolled and well-instrumented experiments, which capture features relevant t o both hydrodynamic and structural response in a single experiment. Aluminu m was chosen for use in this study because it is a well-characterized mater ial. The current experiments span strain rate regimes of over 10(7)/s to le ss than 10(2)/s in a single experiment. The input conditions were extremely well defined. Velocity interferometers were used to record the high strain -rate response, while low strain rate data were collected using strain gaug es. Although the current tests were conducted at a nominal velocity of simi lar to 1.5 km/s, it is the test methodology that is being emphasized herein . Results of a three-dimensional experiment are also presented. (C) 1999 El sevier Science Ltd. All rights reserved.