Kerati Suwanpakpraek^1,3, Baramee Patamaprohm^1,3, Sacharuck Pornpeerakeat^2,3, Arisara Chaikittiratana^1,3,*

CMES-Computer Modeling in Engineering & Sciences, Vol.135, No.3, pp. 1765-1778, 2023, DOI:10.32604/cmes.2023.022523

Abstract

This paper deals with the numerical implementation of the exponential Drucker-Parger plasticity model in the commercial finite element software, ABAQUS, via user subroutine UMAT for adhesive joint simulations. The influence of hydrostatic pressure on adhesive strength was investigated by a modified Arcan fixture designed particularly to induce a different state of hydrostatic pressure within an adhesive layer. The developed user subroutine UMAT, which utilizes an associated plastic flow during a plastic deformation, can provide a good agreement between the simulations and the experimental data. Better numerical stability at highly positive hydrostatic pressure loads for a very high order of exponential… More > Graphic Abstract

L. Teneketzis Tenek¹, E.C. Aifantis^1,2,3

CMES-Computer Modeling in Engineering & Sciences, Vol.3, No.6, pp. 731-741, 2002, DOI:10.3970/cmes.2002.003.731

Abstract A two-dimensional finite element implementation of a special form of gradient elasticity is developed and a connection between classical and the proposed gradient elasticity theory is established. A higher-order constitutive equation is adopted which involves a gradient term of a special form; the higher-order term is precisely the second gradient of the lower-order term. A weak form of the equilibrium equations, based on the principle of virtual work, is formulated for the classical problem. The problem in hand, is solved by means of the finite element method in two steps. First, the displacement field of classical elasticity is computed. Then,… More >

N.A. Dumont ¹, D. Huamán¹

CMES-Computer Modeling in Engineering & Sciences, Vol.101, No.6, pp. 387-419, 2014, DOI:10.3970/cmes.2014.101.387

Abstract The present paper starts with Mindlin’s theory of the strain gradient elasticity, based on three additional constants for homogeneous materials (besides the Lamé’s constants), to arrive at a proposition made by Aifantis with just one additional parameter. Aifantis’characteristic material length g², as it multiplies the Laplacian of the Cauchy stresses, may be seen as a penalty parameter to enforce interelement displacement gradient compatibility also in the case of a material in which the microstructure peculiarities are in principle not too relevant, but where high stress gradients occur. It is shown that the hybrid finite element formulation – as proposed by… More >