Publikacje

Abstract:

Willam’s test [1] is a numerical tension-shear test used to verify inelastic material models at the point level. The test is strain driven and consists of two separate steps: uniaxial tension followed by biaxial tension with shear according to the ratio: e11:e22:g12 = 0.5:0.75:1. A rotation of principal strain and principal stress axes can be observed, which is very fast at the beginning of the test and then slows down tending to an asymptote. As results of the test the graphs of stresses vs dominant strain and changes of principal directions vs dominant strain can be plotted. The responses of different models can be different even though they all have been calibrated in such a way as to give identical results in the uniaxial tension test. The paper presents results of calculations for Willam’s test using the following material models: - concrete damaged plasticity model (CDP) in Abaqus [2] - a combination of plasticity theory and damage mechanics; the model introduces damage parameters in tension and compression, which are used to modify elastic stiffness and the plastic flow is assumed as nonassociated, - concrete smeared cracking model (CSC) in Abaqus [3] - based on the classical theory of plasticity in compression and the fixed smeared crack model in tension, - damage-plasticity model (DAP) [4] - the scalar damage theory is coupled to the plasticity theory, where after unloading irreversible strains are observed, - isotropic damage (IDA) [5] - an upgrade of the damage model which incorporates volumetric-deviatoric decomposition of the elastic operator, - viscoplastic Hoffman consistency model (HVP) [6] – uses the Hoffman yield function in its isotropic form and is enhanced with separate hardening/softening behaviour in tension and compression.

POWRÓT

Strona główna > Publikacje

Verification of different inelastic concrete models at the point level in Willam’s test