Delamination Growth in Graphite/Epoxy Composites Subjected to Cyclic Mode III Loading

Abstract

A study was conducted to characterize the delamination growth behavior in a brittle graphite/epoxy composite under a tearing mode III condition. For this purpose, split canti lever beam specimens were tested under static and fatigue loadings. The static tests pro vided the critical strain energy release rate, G _IIIC, for mode III. From the fatigue tests, the relationships between delamination growth rate and the corresponding strain energy release rate, G_III, were established for two displacement ratios. The results of the present study under the mode III condition are discussed and compared with their counterparts from previous studies involving mode I and mode II. The present results are also discussed in terms of damage tolerance and durability design considerations in composite structures.

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