Tensile property uncertainty in upcycled discontinuous prepreg platelet molded composites considering distributions of platelet shape and size

Tape edge trim (TET) is a by-product of the unidirectional prepreg tape manufacturing process. Transformation into platelets through upcycling enables its use as a compression molding compound, eliminating the need to dispose of high-performance constituent material through environmentally harmful methods. TET-based Prepreg Platelet Molded Composites (PPMC) are shown to morphologically and mechanistically belong to the same class of discontinuous prepreg composites as those derived from constant size pristine prepreg platelets. The distinction lies in the statistical distribution of platelet size and shape. This additional geometric randomness introduces further uncertainty in the effective mechanical properties of TET PPMCs and motivates the need to quantify its influence through both experimental and computational analysis. This study investigates the behavior of TET-based PPMC composites under uniaxial tensile testing compared to conventional PPMCs. The proposed numerical framework combines an approximate meso-structural generation algorithm with a continuum damage mechanics (CDM) and cohesive zone modeling (CZM)- based finite element model to capture intra- and interlaminar damage modes. The predicted effective stiffness, strength, and their variability determined were validated through experimental testing. PPMC/TET are shown to be defined by sensitivity to the largest platelets within the coupon. Compared to conventional PPMCs, PPMC/TET possessed higher mean strength and increased variability due to presence of large platelets.