A consistency assessment of coupled cohesive zonemodels for mixed-mode debonding problems
Journal Title: Frattura ed Integrità Strutturale - Year 2014, Vol 8, Issue 29
Abstract
Due to their simplicity, cohesive zone models (CZMs) are very attractive to describe mixed-modefailure and debonding processes of materials and interfaces. Although a large number of coupled CZMs havebeen proposed, and despite the extensive related literature, little attention has been devoted to ensuring theconsistency of these models for mixed-mode conditions, primarily in a thermodynamical sense. A lack ofconsistency may affect the local or global response of a mechanical system. This contribution deals with theconsistency check for some widely used exponential and bilinear mixed-mode CZMs. The coupling effect onstresses and energy dissipation is first investigated and the path-dependance of the mixed-mode debondingwork of separation is analitically evaluated. Analytical predictions are also compared with results from numericalimplementations, where the interface is described with zero-thickness contact elements. A node-to-segmentstrategy is here adopted, which incorporates decohesion and contact within a unified framework. A newthermodynamically consistent mixed-mode CZ model based on a reformulation of the Xu-Needleman model asmodified by van den Bosch et al. is finally proposed and derived by applying the Coleman and Noll procedurein accordance with the second law of thermodynamics. The model holds monolithically for loading andunloading processes, as well as for decohesion and contact, and its performance is demonstrated throughsuitable examples.
Authors and Affiliations
R. Dimitri, M. Trullo, G. Zavarise, L. De Lorenzis
Keywords
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- EP ID EP131745
- DOI 10.3221/IGF-ESIS.29.23
- Views 64
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