Randomly reinforced composites: properties, failure and aspects of material design

This article concerns several aspects of mechanical properties and tensile failure of randomly reinforced, chopped fiber strand, polymeric composites. Scatter in material properties and their dependence on sample size are investigated by means of an analytical/computational model and compared against the experimental data. Predictions are also provided for deviations from isotropy and homogeneity. Failure is modeled in a manner akin to the methodology employed for laminated composites and predictions are compared against the experimental data. The model is utilized to select combinations of multi-size strands so as to minimize material inhomogeneity.