Effect of Volume Fraction and Fiber Distribution on Stress Transfer in a Stochastic Framework of Continuous Fiber Composite: A Micromechanical Study

TL;DR

This study investigates how fiber volume fraction and distribution affect stress transfer in fiber reinforced composites, revealing that fiber arrangement and size significantly influence stress transfer efficiency and strength recovery.

Contribution

It provides a detailed micromechanical analysis of stress transfer in composites considering various fiber arrangements and volume fractions, highlighting the importance of fiber size and distribution.

Findings

Fiber distribution does not follow standard statistical distributions.

Fiber cross-sectional size critically influences strength recovery.

Periodic fiber arrangements improve stress transfer over random arrangements.

Abstract

In fiber Reinforced Composites (FRC) fiber breakage is a common phenomenon resulting in stress concentration. This high stress gets transfer in the vicinity of the breakage which is quantified by Stress Transfer Coefficient (STC). In this paper, an attempt is made to check the effect of fiber volume fraction and the distribution of the fibers on STC and ineffective length. The fiber volume fraction is changed considering three cases: 1) by changing the number of fibers, 2) by changing the dimension of the Represntative Volume Element (RVE) and 3) by changing the fiber radius. Cases with change in dimension of RVE and change in fiber radius, periodic and semi-random arrangents of fibers are considered. From the analysis of 200 RVE's for each volume fraction in random and semi-random arrangements, it is observed that the distribution of STC does not follow any standard distribution, even if the fiber arrangement follows the normal distribution. The fiber cross-sectional dimension plays a critical role in regaining the broken fiber strength. The periodic arrangement of fibers can be said to be beneficial over the random arrangement considering the stress transfer from the broken fiber.