Microscopic stresses of discontinuous fiber reinforced composites under thermal and mechanical loadings – Finite element simulations and statistical analyses

The microscopic stresses of the discontinuous fiber reinforced composites under thermal and mechanical loadings have not been intensively studied as they cannot be directly measured. Thus, a finite element simulation associated with a suitable analysis strategy is required to reveal the microscopic stresses of these composite materials, though it is challenging owing to the randomly distributed fibers. In this study, the microscopic stresses in an actual composite are simulated by using finite element method and combining techniques of morphology transformation, massively parallel computing, and edge effect removal. The probability density of the von Mises stress of the resin exhibits a single peak and covers a wide range, following the Burr statistic model regardless of the loading type. The external mechanical loading and material modulus, rather than the thermal loading, are the main factors affecting the probability density. The reason for the appearance of the lower and upper values of the von Mises stress of the resin is also discussed. The characteristics of the discontinuous fiber reinforced composite evaluated in this preliminary study are beneficial to understand the mechanical properties of such new composites.