Penetration of rod projectiles in semi-infinite targets : a validation test for Eulerian X-FEM in ALEGRA.

Technical Report · Fri Mar 01 04:00:00 EST 2013

DOI:https://doi.org/10.2172/1088058· OSTI ID:1088058

Park, Byoung Yoon; Leavy, Richard Brian ^[1]; Niederhaus, John Henry J.

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1. U.S. Army Research Laboratory, Aberdeen Proving Grounds, MD

The finite-element shock hydrodynamics code ALEGRA has recently been upgraded to include an X-FEM implementation in 2D for simulating impact, sliding, and release between materials in the Eulerian frame. For validation testing purposes, the problem of long-rod penetration in semi-infinite targets is considered in this report, at velocities of 500 to 3000 m/s. We describe testing simulations done using ALEGRA with and without the X-FEM capability, in order to verify its adequacy by showing X-FEM recovers the good results found with the standard ALEGRA formulation. The X-FEM results for depth of penetration differ from previously measured experimental data by less than 2%, and from the standard formulation results by less than 1%. They converge monotonically under mesh refinement at first order. Sensitivities to domain size and rear boundary condition are investigated and shown to be small. Aside from some simulation stability issues, X-FEM is found to produce good results for this classical impact and penetration problem.

• Research Organization: United States. Department of the Army. Army Research Laboratory, Aberdeen Proving Ground, MD; Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA)
• DOE Contract Number: AC04-94AL85000
• OSTI ID: 1088058
• Report Number(s): SAND2013-1863; 456370
• Country of Publication: United States
• Language: English