Progressive damage arrest mechanism in tailored la

Authors: De Xie Sherrill B Biggers

Publish Date: 2008/02/01

Volume: 21, Issue: 1, Pages: 62-72

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Abstract

This study addresses the effectiveness of a simple stiffness tailoring concept to delay damage initiation control damage progression and improve residual strength in tensileloaded composite plates with a central circular cutout The tailoring concept is to simply reposit all axially oriented 0° material into regions near the edge of the plate away from the cutout This tailoring is done in a way so as not to affect the weight of the plate This accomplishes several beneficial changes in the way that the plate resists loading with no increases in material cost or weight Lowering the axial stiffness of the laminate surrounding the cutout lowers the stress concentration Increasing the axial stiffness near edges of the plate attracts loading away from the vicinity of the cutout to further lower stresses in the critical cutout region This study focuses on inplane response including damage progression and residual strength as a function of the degree of tailoring and cutout size Strength and stiffness properties typical of IM7/85517 preperg material were assumed and a modified version of the Hashin failure criteria was used to identify the local damage Results show that tailoring can significantly increase the damage initiation load and the residual strength In some cases observed evidence shows that tailoring performs as a damage arrest mechanism

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