Papers by Keyword: Element-Free Galerkin Method EFGM

Abstract: The aim of the present study is evaluation of the element-free Galerkin method (EFGM) in progressive damage analyses of composite laminates. For this purpose, an orthotropic EFGM formulation is employed which is based on the first-order shear deformation theory (FSDT). In progressive damage analysis, the Hashin’s type failure criteria and their degradation rules are used. The obtained damage results from EFGM are compared with the experimental and FEM results.

Abstract: The meshless methods effectively deal with large material distortion simulation. Based on the rigid (visco)plastic material model, the element-free Galerkin method (EFGM) is introduced to simulate the metal forming processes. Aiming at the volume locking and pressure oscillation during EFGM analysis, a volumetric strain rate mapping method is proposed based on pressure projection method. The releasing algorithm is established by modifying the volumetric strain rate in the functional equation. The volumetric strain rate calculated according to velocity field is mapped onto a lower-order space to reduce the number of independent discrete constrain equations. The numerical example shows that the releasing algorithm can effectively eliminate the volumetric locking and pressure oscillation without the expense of employing large support size in the rigid-plastic meshless method.

Abstract: Superplastic large deformation problems always meet handicaps associated with severe mesh distortion and iterative remeshing when traditional mesh-based numerical approaches are used. To eliminate these difficulties, meshless simulation of element free Galerkin method (EFGM) for rigid-viscoplastic(RVP) model and incompressible materials is built upon the Moving Least Squares (MLS) approximation and modified Markov variational principles. Also, a numerical quadrature that aligns integration cells with the local supports of shape functions is presented to compute integrations involved in the objective functions. Satisfying results of a superplastic upsetting example with very large compression ratio demonstrate the feasibility and accuracy for the meshfree method to simulate superplastic large deformation process.