Simplified Stochastic Modeling and Simulation of Unidirectional Fiber Reinforced Composites

Stochastic prediction of the failure strength of composite materials has been the subject of research for the last four decades. These studies have generally focused on expensive materials with high quality control for use in aerospace applications. For these applications it has been economically feasible to obtain reliable statistical data. To extend this research to the analysis of composites with widespread use in civil engineering, the complicated models developed in the past need to be simplified. This paper proposes a simplified stochastic two-dimensional model to predict the strength distribution of single-ply unidirectional composites. The model is studied via Monte Carlo simulation and accounts for the following parameters: specimen size, fiber strength distribution, fiber-matrix properties and load transfer at broken fibers. The classical load sharing rules to model the load redistribution at broken fibers are modified to consider different material properties. A parametric study investigating the parameters that affect the strength and the failure pattern of the composite is presented. The numerical results are consistent with experimental data analyzed. The study is used to quantify the effect of various material and geometric characteristics on resultant performance and failure properties.