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WARP3D-Release 10.8: Dynamic Nonlinear Analysis of Solids using a Preconditioned Conjugate Gradient Software ArchitectureThis report describes theoretical background material and commands necessary to use the WARP3D finite element code. WARP3D is under continuing development as a research code for the solution of very large-scale, 3-D solid models subjected to static and dynamic loads. Specific features in the code oriented toward the investigation of ductile fracture in metals include a robust finite strain formulation, a general J-integral computation facility (with inertia, face loading), an element extinction facility to model crack growth, nonlinear material models including viscoplastic effects, and the Gurson-Tver-gaard dilatant plasticity model for void growth. The nonlinear, dynamic equilibrium equations are solved using an incremental-iterative, implicit formulation with full Newton iterations to eliminate residual nodal forces. The history integration of the nonlinear equations of motion is accomplished with Newmarks Beta method. A central feature of WARP3D involves the use of a linear-preconditioned conjugate gradient (LPCG) solver implemented in an element-by-element format to replace a conventional direct linear equation solver. This software architecture dramatically reduces both the memory requirements and CPU time for very large, nonlinear solid models since formation of the assembled (dynamic) stiffness matrix is avoided. Analyses thus exhibit the numerical stability for large time (load) steps provided by the implicit formulation coupled with the low memory requirements characteristic of an explicit code. In addition to the much lower memory requirements of the LPCG solver, the CPU time required for solution of the linear equations during each Newton iteration is generally one-half or less of the CPU time required for a traditional direct solver. All other computational aspects of the code (element stiffnesses, element strains, stress updating, element internal forces) are implemented in the element-by- element, blocked architecture. This greatly improves vectorization of the code on uni-processor hardware and enables straightforward parallel-vector processing of element blocks on multi-processor hardware.
Document ID
19990032494
Acquisition Source
Langley Research Center
Document Type
Other
Authors
Koppenhoefer, Kyle C. (Illinois Univ. Urbana-Champaign, IL United States)
Gullerud, Arne S. (Illinois Univ. Urbana-Champaign, IL United States)
Ruggieri, Claudio (Illinois Univ. Urbana-Champaign, IL United States)
Dodds, Robert H., Jr. (Illinois Univ. Urbana-Champaign, IL United States)
Healy, Brian E. (Exxon Production Research Company Houston, TX United States)
Date Acquired
September 6, 2013
Publication Date
September 1, 1998
Publication Information
ISSN: 0069-4274
Subject Category
Computer Programming And Software
Report/Patent Number
UILU-ENG-95-2012
SRS-607
Funding Number(s)
CONTRACT_GRANT: NAG2-1126
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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