Novel Analytical Model of Stress Concentration around Broken Fibers of Unidirectional Composite Plate

Bachir Bouhamida,Abderrazek Merzoug

doi:10.3311/ppme.16062

Abstract

During the fiber fracture of unidirectional composite a distribution of stress around the neighbored fibers happens, this mechanism is called the local redistribution efforts. Referring to the "shear lag" method, the researches wanted to predict the stress concentration in the surrounding area of broken fibers as well as the longitudinal resistance of the unidirectional composite which presents a fiber breaking. The goal of this paper is to develop a new probabilistic model of unidirectional composite plate to calculate the stress concentration at the broken fibers and their neighboring fiber intact. The "shear lag" method has been generalized to see the broken fibers interference on the stress concentration factor variation of surrounding sound fibers.

Highlights

The composite materials are using in various industries due to their high mechanical performance
The goal of this paper is to develop a new probabilistic model of unidirectional composite plate to calculate the stress concentration at the broken fibers and their neighboring fiber intact
The "shear lag" method has been generalized to see the broken fibers interference on the stress concentration factor variation of surrounding sound fibers

Summary

Introduction

The composite materials are using in various industries due to their high mechanical performance. The "shear lag" is the wide method used to modeling the interaction of fiber/matrix It leads to predict the stress concentration in the surrounding area of broken fibers as well as the longitudinal resistance of unidirectional composite include broken fibers. They determined the effective fiber length to estimate the optimum tensile resistance They made a shear model analysis of unidirectional composite materials, where neglected the effect of stress concentration on the neighbored fibers to that broken was taken. Using a square shaped structure of surrounding fibers, the researcher determined the resistance of Ti-6Al-4V metallic matrix reinforced by SiC They showed that fiber breaking takes place in a random direction. Rouhi and Rais-Rohani [12], have studied the elastic properties of a random carbon nanofiber (CNF) reinforced a vinylester matrix under buckling loading They introduced the micromechanical approaches on the mathematical modeling. To calculate the stress concentration factor, we must calculate the derivatives of displacements along with the three following formulae: the front, center and back: dui, j,k

Ef ui

Radius of the fiber rf Disturbance distance xp