A stiffness model has been proposed to predict elastic constants of twisted yarn composites. The model is based upon the unit cell structure, the coordinate transformation, and the volume averaging of compliance constants for constituent materials. Fo...
A stiffness model has been proposed to predict elastic constants of twisted yarn composites. The model is based upon the unit cell structure, the coordinate transformation, and the volume averaging of compliance constants for constituent materials. For the correlation of analytic result with experiments, composite samples of various yarn twist angles were tested, and strength and Young`s modulus under tensile, compressive, and shear loading have been obtained. The sample was fabricated by the RTM process using glass yarns and epoxy resin. The correlations of elastic constants showed relatively good agreements. The model provides the predictions of the three-dimensional engineering constants, which are valuable input data for the analytic characterization of textile composites made of twisted yarn.