Viscoplastic Regularization of Local Damage Models: A Latent Solution

M.S. Niazi; H.H. Wisselink; V. Timo Meinders

doi:10.4028/www.scientific.net/KEM.504-506.845

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HomeKey Engineering MaterialsKey Engineering Materials Vols. 504-506Viscoplastic Regularization of Local Damage...

Viscoplastic Regularization of Local Damage Models: A Latent Solution

Abstract:

Local damage models are known to produce pathological mesh dependence in finite element simulations. The solution is to either use a regularization technique or to adopt a non-local damage model. Viscoplasticity is one technique which can regularize the mesh dependence of local damage model by incorporating a physical phenomenon in the constitutive model i.e. rate effects. A detailed numerical study of viscoplastic regularization is carried out in this work. Two case studies were considered i.e. a bar with shear loading and a sheet metal under tensile loading. The influence of hardening / softening parameters, prescribed deformation rate and mesh size on the regularization was studied. It was found that the primary viscoplastic length scale is a function of hardening and softening parameters but does not depend upon the deformation rate. Mesh dependency appeared at higher damage values. This mesh dependence can be reduced by mesh refinement in the localized region and also by increasing the deformation rates. The viscoplastic regularization was successfully used with a local anisotropic damage model to predict failure in a cross die drawing process with the actual physical process parameters.

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Periodical:

Key Engineering Materials (Volumes 504-506)

Pages:

845-850

DOI:

https://doi.org/10.4028/www.scientific.net/KEM.504-506.845

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Cite this paper

Online since:

February 2012

Authors:

M.S. Niazi, H.H. Wisselink, V. Timo Meinders

Keywords:

Local Damage Models, Modified Lemaitre’s Damage Model, Pathological Mesh Dependence, Primary Viscoplastic Length Scales, Secondary Viscoplastic Length Scales, Strain Rate Hardening, Viscoplastic Regularization

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