Penetration Mechanics with an Arbitrary Lagrangian Eulerian Finite Element Code

摘要

Methodologies for Arbitrary Lagrangian Eulerian (ALE) formulations for the treatment of penetration problems are studied. These methods are attractive because they would permit far more economical simulation of penetration problems by avoiding the extreme crushing of the elements at the penetrator/target interface. Previous to these developments, computer simulations of two and three dimension problems are so time-consuming (2 to 24 hours on the largest computer) that they cannot be made within the normal framework of engineering analysis and decision making. These methods offer the potential of an order of magnitude reductions in running time. Five aspects of ALE formulations are studied: the convergence and stability of multitime step (subcycling) algorithms, development of ALE constitutive laws which are derivable from Lagrangian constitutive equations, and development of mapping procedures for the mesh so that excessive distortion is avoided. In the research program, these aspects are studied in conjunction with realistic computations of two dimensional penetration problems. Keywords: Arbitrary Lagrangian Eulerian; Stability; Multitime step; Finite elements; Petrov Galerkin Finite Elements; Subcycling; Impact penetration; Transient solutions; Strain softening.