Assessment of the shear properties of thermoplastic composites using the ±45 and the v-notched rail shear method

Composite materials consisting of thermoplastic matrix and glass fibers are catching on both in aeronautics and automotive industry as they comprise a series of advantages regarding their mechanical performance and their recyclability. Nevertheless, some notable drawbacks have been noticed related to the fabrication process affecting their in-plane shear properties. For assessing the in-plane shear behavior of composite laminates, a relatively high number of standards have been proposed. Each of these testing methods appear to have several advantages and drawbacks mostly related to the way the load is applied, the stress uniformity and the applicability to various material architectures. In the present work, the modified V-Notched Rail Shear and the ±45o shear testing methods are applied to short and textile glass fiber reinforced thermoplastics aiming to assess the effect of the fabrication method and the fiber strands direction both at ambient and higher temperature. Consecutively, the results obtained from the two different testing methods are compared revealing a relatively good agreement while, in parallel, the stress uniformity and the local failures observed on the specimens are analyzed.