To avoid unwanted defects such as out-of-plane wrinkles during the forming process of woven reinforcements, it is important to take into account in-plane shear deformation. The study presented here used a bias extension test to determine experimentally the in-plane shear behavior of out-of-autoclave 8-harness and 5-harness satin woven carbon/epoxy prepregs. The test was performed at different displacement rates, while changes in tow geometry with respect to applied force were observed. The various stages of deformation and the onset of wrinkling during the shearing of woven fabrics were determined by a digital image correlation (DIC) technique. An infrared (IR) heater was used to investigate the effect of different elevated temperatures on in-plane shear properties. The results of the study show that a rise in temperature results in decreased viscosity of the resin and shear force. This decrease in viscosity, in turn, increases the allowable shear deformation, which results in a reduction of wrinkling. Moreover, the fabric architecture and yarn size had great influence on the in-plane deformation results.
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