Considering the Randomness of Mechanical Properties in Simulations of Discontinuous Fiber Reinforced Composites

Abstract

Discontinuous Fiber Reinforced Polymer (DFRP) composites often display large variations in mechanical properties and large difference between tensile and flexural strengths. This work investigates a glass fiber Sheet Molding Compound (SMC) composite. The experimental results show that the flexure strength is 86% higher than the tensile strength. Using the mean mechanical properties measured in tensile, compression and shear tests would result in underprediction of the flexural behavior. The randomness of the tensile strengths of DFRP composites is discussed. A Weibull distribution model comprising of both the tensile and flexural strengths is proposed. The use of this model in FEA is demonstrated.