Quantifying inter- and intra-ply shear in the deformation of uncured composite laminates

Abstract

Abstract Understanding the bending mechanics of uncured carbon fiber prepreg is vital for modeling forming processes and the formation of out-of-plane wrinkling defects. This article presents a modification of standard dynamic mechanical analysis (DMA) to characterize the viscoelastic bending mechanics of uncured carbon fiber prepreg using Timoshenko beam theory, along with an updated model describing inter-ply shear in uncured laminates. By post-processing DMA results, the analysis provides temperature and rate-dependent values of inter and intra-ply shear stiffness for a carbon fiber laminate and each individual ply with experimental results for AS4/8552 presented. The new methodology provides a means to parametrize process models, and also gives an indication of optimal manufacturing conditions to enable defect-free forming and consolidation processes. Graphical abstract