Structure-property relationship for a prepreg platelet molded composite with engineered meso-morphology

Abstract

The objective of this work was to develop a finite-element based computational model to investigate the complex three-dimensional load transfer from the known meso-structure of a prepreg platelet molded composite (PPMC) system with a layered planar morphology and deterministic orientation state, where platelets are aligned and staggered in each layer. Three-dimensional stress transfer was studied for the prediction of failure under tensile loading. A finite-element model was used for the analysis of the composite structure-property relationship. Variability of meso-structure geometry was shown to control the distributed tensile properties of a PPMC laminate. Platelet length-to-thickness and length-to-width ratios were found to control the composite effective strength. Experimental analysis was used to complement the results of theoretical studies. A PPMC meso-structure with deterministic orientation state of engineered morphology was found to provide enhanced effective tensile properties with reduced variability as compared to stochastic prepreg platelet meso-structure. The mechanisms leading to enhanced structural performance were (i) the improved hierarchical structure of the platelet system and (ii) the ability to define the fiber orientation state of the composite system.