Continuous fiber reinforced Polymer Matrix Composites are replacing traditional steel for di fferent load bearing applications due to their high specific strength and stiffness. Micromechanical modeling through finite element analysis of representative volume element has been widely used by the researchers for prediction of elastic and strength properties of composites, and also for studying different damage mechanisms like matrix cracking, fiber breakage and interface failure. UDFRP composites also exhibit statistical variations in the material properties. It is essential to acknowledge these variations and use a statistics-based strength property for designing composite structures. There is a lack of literature on prediction of statistics of strength distribution through micromechanical modeling. In the present work, the effect of non-uniformity in inter-fiber distance on statistics of strength distribution of UDFRP composite is studied through computational micromechanics. Variation of mean value, standard deviation and B-basis of failure initiation strength with the amou nt of non-uniformity in fiber distribution is studied. It has been found that, in addition to mean value, non-uniformity in fiber distribution also has significant influence on standard deviation of strength distribution.
RVE size influences its representativeness. One of the approaches used for determine the size of RVE is to perform convergence studies on RVE size for various parameters like Young’s Modulus, mean von Mises stress, maximum von Mises stress etc. In literature, studies for RVE size has been done either for a periodic (square or hexagon) or random fiber distribution. However, literature does not exist on RVE sizing for a quantified non-uniformity in fiber distribution. A research to explore the relation between degree of irregularity in fiber distribution and corresponding RVE size is conducted in the present study. It is found that non-uniformity in fiber distribution significantly influences size of RVE and using an RVE without size convergence studies may lead to significant error. Stress distribution and failure initiation in constituents of UDFRP composites is usually studied through FE analysis of RVE which is computationally expensive and time consuming. The present st udy also proposes an analytical model through which stress variation and failure initiation in the constituents of UDFRP composite can be obtained in simple and reliable way. The results of analytical model are compared with FE simulations and good agreement is observed.