Effect of microstructure on the response of composite tubes
This paper addresses the effects of changes in the fiber content in the individual layers of a composite tube and the presence of resin-rich interplay regions on the torsional response of the tube. A micromechanics-based procedure is outlined to correct the properties of unidirectional graphite/epoxy obtained from flat coupon tests in order to account for the lower fiber volume fraction in the individual layers of a composite tube made from the same material. The corrected properties are used as input parameters to an analytical model developed to predict the response of composite tubes subjected to combined axial/torsion loading. It is illustrated that when the corrected properties and the resin-rich regions are included in the analysis, good correlation with experimental data is obtained.