Laminate wrinkling scaling laws for ideal composites

For the double diaphragm forming process, laminate wrinkling is a major failure mode for both thermoplastic and thermoset composites. In this paper, we compare experimental observations on the wrinkling of aligned fibre thermoset composites with theoretical scaling laws based on ideal kinematics (i.e. constant interfibre spacing and constant thickness). Differences between the ideal predictions and actual results are explained in terms of deviations from ideal kinematics. Differences between thermoplastic and thermoset composites are discussed, and an empirical scaling law for the effect of part size on wrinkling is given.