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Dynamic Lagrangian computations for solids, with variable nodal connectivity for severe distortions
Author(s) -
Johnson Gordon R.,
Stryk Robert A.,
Dodd Jack G.
Publication year - 1986
Publication title -
international journal for numerical methods in engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.421
H-Index - 168
eISSN - 1097-0207
pISSN - 0029-5981
DOI - 10.1002/nme.1620230313
Subject(s) - computation , grid , node (physics) , variable (mathematics) , lagrangian , finite element method , topology (electrical circuits) , mathematics , computer science , geometry , mathematical optimization , algorithm , mathematical analysis , structural engineering , engineering , combinatorics
This paper presents an algorithm for dynamic Lagrangian computations for solids, in plane strain geometry, with variable nodal connectivity to allow for severe distortions. The nodes are somewhat analogous to flexible circular disks. When they move closer together than their equilibrium distance they generate compressive, repulsive forces. Conversely, when they move apart, they generate tensile, attractive forces. Material strength effects are also included. Because a node can only be affected by its ‘neighbour’ nodes, the approach has been designated the ‘NABOR’ approach. The key to this approach is that it is possible to have variable nodal connectivity—a node can acquire new neighbours, thus allowing all forms of distortion. The NABOR algorithm has been incorporated as an option into the explicit finite element code, EPIC‐2. By using both the NABOR grid and the EPIC‐2 finite element grid together, it is possible to perform Lagrangian computations for a wide range of problems.