Failure mechanism identification for multiaxially loaded woven composites using hybrid infrared-visible light correlation

This paper presents a detailed analysis of 3-mm thick woven glass fiber composite samples subjected to complex in-plane loading regimes. Three butterfly shaped samples, each with two V-notches in the gauge region, were tested under tensile, simple shear, and combined tensile/shear loading using a modified Arcan fixture. An advanced optical setup, consisting of two visible-light cameras and one infrared camera, was utilized. Hybrid multiview correlation was employed to measure surface displacement, strain, and Lagrangian temperature fields. The highest stress levels were achieved for the tensile loading configuration; for the combined tensile/simple shear loading history, the highest strain levels were reached. The combined loading exhibited features of both tensile and simple shear loadings. The findings revealed phenomena corresponding to thermoelastic effect for tensile and combined loadings, but not in the shear-only case. Additionally, during combined loading, the shear strains were dominant until significant damage occurred, after which the strains in the loading direction took over. The combined evaluation of strained bands and temperature fields enables for the identification of damage mechanisms.