Three-Dimensional Cohesive Modeling of Impact Damage of Composites

Author: Yu, Chengxiang Rena

Year: 2001

Degree: Dissertation (Ph.D.)

Advisor: Ortiz, Michael

Committee Members: Rosakis, Ares J.; Beck, James L.; Hou, Thomas Y.; Ortiz, Michael; Pandolfi, Anna

Option: Aeronautics; Applied And Computational Mathematics

DOI: 10.7907/nd8e-tc84

Abstract

The objective of this work is to establish the applicability of cohesive theories of fracture in situations involving material interface, material heterogeneity (e.g., layered composites), material anisotropy(e.g., fiber-reinforced composites), shear cracks, intersonic dynamic crack growth and dynamic crack branching. The widely used cohesive model is extended to orthotropic range. The so-developed computational tool, completed by a self-adaptive fracture procedure and a frictional contact algorithm, is capable of following the evolution of three-dimensional damage processes, modeling the progressive decohesion of interfaces and anisotropic materials. The material parameters required by cohesive laws are directly obtained from static experiments. The ability of the methodology to simulate diverse problems such as delamination between fibers of graphite/epoxy composites, as well as sandwich structures and branching within brittle bulk materials has been demonstrated.

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