
Accession Number : ADA329723
Title : Crack Propagation by ElementFree Galerkin Methods
Descriptive Note : Final rept. 1 Jan 9431 Mar 97
Corporate Author : NORTHWESTERN UNIV EVANSTON IL DEPT OF CIVIL ENGINEERING
Personal Author(s) : Belytschko, Ted
PDF Url : ADA329723
Report Date : 15 MAY 1997
Pagination or Media Count : 86
Abstract : The elementfree Galerkin (EFG) method is a meshfree method for solving solid mechanics problems with an approximation based only on nodes. It is developed here for linear elastic fracture problems. Smoothing of meshfree approximations near nonconvex boundaries is done by three methods: (1) the diffraction method, in which the nodal domain of influence wrapped a short distance around a boundary, (2) the transparency method, which is described only for cracks, yields continuous approximations by gradually severing the domains of influence near crack tips, and (3) the 'seethrough' method, or continuous line criterion, which does not enforce a discontinuity or crack if the tip is within the domain of influence. Two methods for enriching EFG approximations for linear elastic fracture problems are described: extrinsic enrichment involves adding the form of the solution to the trial function; for intrinsic enrichment, the EFG basis is expanded to include terms from the near tip crack solution. Several problems are solved to illustrate the effectiveness of EFG crack propagation with smoothing and enrichment.
Descriptors : *FRACTURE(MECHANICS), *CRACK PROPAGATION, COMPUTERIZED SIMULATION, ELASTIC PROPERTIES, APPROXIMATION(MATHEMATICS), BOUNDARY VALUE PROBLEMS, LEAST SQUARES METHOD, FATIGUE(MECHANICS), APPLIED MATHEMATICS, GALERKIN METHOD.
Subject Categories : Mechanics
Distribution Statement : APPROVED FOR PUBLIC RELEASE