The Influence of Fiber Distribution and Voids on the Tensile Strength of Polymer Composite Materials

Three types of material variations commonly introduced during the processing of polymeric matrix composite materials are considered. These are (i) deviations from the local fiber volume fraction from the design specifications, (ii) non-uniformity in the inter-fiber spacing, and (iii) the presence of substantial levels of local void distribution. The influence of these variabilities on the longitudinal tensile strength of unidirectional composite material is evaluated. For composite materials with uniform fiber distribution, the tensile strength slightly dropped as the fiber volume fraction was increased. The non-uniformity in the inter-fiber spacing and the presence of significant levels of voids was found to have a more adverse influence on the tensile strength.