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Non-local averaging in composite micro-mechanical material models

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Strain-softening material models have conventionally had a pathological mesh sensitivity in finite element simulations and composite materials are indifferent to this problem. Spurious localization is inherent to the structural problem in strain-driven softening. | Non-local averaging in composite micro-mechanical material models Engineering Solid Mechanics 7 2019 263-278 Contents lists available at GrowingScience Engineering Solid Mechanics homepage www.GrowingScience.com esm Non-local averaging in composite micro-mechanical material models Sandeep Medikondaa and Ala Tabieia a Department of Mechanical and Materials Engineering University of Cincinnati Cincinnati OH USA A R T I C L EI N F O ABSTRACT Article history Strain-softening material models have conventionally had a pathological mesh sensitivity in finite Received 7 July 2019 element simulations and composite materials are indifferent to this problem. Spurious localization Accepted 6 August 2019 is inherent to the structural problem in strain-driven softening. This limitation is caused as the Available online partial differential equations that govern the structural problem become ill-posed as the tangent 6 August 2019 Keywords modulus becomes negative for which uniqueness of the solution with respect to the spatial Unidirectional composites discretization is lost. This causes the numerical results to unrealistically concentrate in a single Micro-mechanical model layer of elements. A basic theory of overcoming mesh sensitivity is the non-local continuum Continuum damage mechanics theory. In this work three different non-local models with isotropic weight function have been Non-local damage proposed and implemented to work in conjunction with a composite micro-mechanical material Finite Element Method model. The effect of a weighing function in each of these formulations has been studied in detail. LS-DYNA All three non-local formulations have been observed to produce a nice smeared effect of damage unlike the local damage models. 2019 Growing Science Ltd. All rights reserved. 1. Introduction The exceptional ability of composite materials to absorb a high amount of kinetic energy during impact loadings combined with a high strength-to-weight ratio makes their use .