Analytical evaluation of stress state in braided orthotropic composite cylinders under lateral compression

This paper deals with the analytical modelling of elastic stress state inside RTM-moulded braided composite cylinders under lateral compression. Taking into account the radial stresses, our modelling is based on the Fourier series development of the π-periodic symmetric loading, deriving from the Hertzian contact law. The experimental part describes the quasi-static delamination under lateral compression of RTM-moulded carbon–epoxy rings, made from braided two-dimensional (2D) tubular preforms and DGEBA-IPD resin. The theoretical part shows a mesoscopic computation of transverse shear stresses is needed in order to explain the locations of the brittle failures. We eventually introduce the notion of an equivalent virtual major crack occurring at a critical value of displacement in order to provide a simplified representation of crack onset and energy release.