THE TRANSVERSE POISSONS RATIO IN FIBER-REINFORCED LAMINAE BY MEANS OFA HYBRID EXPERIMENTAL APPROACH

An approximate theoretical analysis, based on CLT principles and the g eneralized 3D expression of Hooke's law, was performed to correlate th e through-the-thickness thermal expansion coefficient of a symmetric c ross-ply laminate, [(0/90)(n)]s, and the transverse Poisson's ratio of the building laminae. The purpose of the theoretical study was to der ive a simple relation capable of predicting with sufficient accuracy t he transverse Poisson's ratio of a fiber composite lamina in terms of experimentally measured values of thermal expansion coefficients. In t he context of the present investigation the thermal expansion behaviou r of two carbon fiber reinforced epoxy systems was defined experimenta lly and application of the proposed method gave predictions for the tr ansverse Poisson's ratio which were found in agreement with published data of similar composite materials. The method introduced herein may constitute (upon further verification) a valid experimental technique for the evaluation of transverse Poisson's ratio of fiber reinforced l aminae.