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Mathematical Problems in Engineering
Volume 2015, Article ID 145629, 11 pages
http://dx.doi.org/10.1155/2015/145629
Research Article

3D Gradual Material Degradation Model for Progressive Damage Analyses of Unidirectional Composite Materials

1School of Astronautics, Beihang University, Beijing 100191, China
2Institute of Solid Mechanics, Beihang University, Beijing 100191, China

Received 15 September 2014; Accepted 1 December 2014

Academic Editor: Chenfeng Li

Copyright © 2015 Libin Zhao et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

A new 3D constitutive model for progressive damage analyses of unidirectional composite materials is presented, in which several important damage phenomena for the composite materials, such as the interfiber crack orientation, coupling of fiber failure and interfiber failure under longitudinal loads, closure effect for interfiber cracks, and longitudinal compressive behaviors under transversal constraints, have been considered comprehensively. A modified maximum stress failure criterion has been used for the damage onset prediction and a linear damage model has been adopted to establish the evolution rules of different damage. Numerical analyses with the model proposed have been implemented by using the subroutine UMAT in commercial software ABAQUS. Progressive damage analyses and static tensile experiments of a group of double-lap composite bolted joints have been carried out to validate the model proposed. Good agreements between the numerical and experimental results have been obtained.