Elasto-Plastic Analysis of Plate Using ABAQUS

Abstract

Plates and shells are very important parts of engineering structures. The performance of structures depends on accurate assessment of the behaviour of all such elements. Accurate valuations of the maximum load the structure can carry, along with the equilibrium path followed in elastic and inelastic range emphasize the importance of material non-linearity to understand the realistic behaviour of structures. Modelling elements in the inelastic range incorporating the theory of plasticity is complex and lengthy and demands for heavy computations. Elastic-Plastic (with or without strain hardening) is a trivial issue in modelling the material (for both uniaxial and multi-axial Von Mises criteria), in numerical procedures like FEM or in modelling using commercial software. ANSYS or ABAQUS contained already defined material subroutines for such behaviour. The objective of this study is to have better understanding how ABAQUS performs nonlinear analyses of plate under uniformly distributed load incorporating material nonlinearity. Two material behaviours are considered perfectly plastic and linear strain hardening. The results are validated with reference data from Owen & Hint on (1980) and results obtained from FEM numerical solution. The results are compared in terms of load deflection diagrams, first yield load, collapse load and plastic or yield flow. The effect of thickness and boundary conditions are also studied. ABAQUS results and numerical results are found to be in good agreements. The plastic flow patterns clearly depict the perfectly plastic and isotropic strain hardening behaviours and also follow the patterns given by Yield line analysis of slabs. The patters obtained from ABAQUS and numerical solutions are compared and found to be similar.