Reversible Rail Shear Apparatus Applied to the Study of Woven Laminate Shear Behavior

Abstract

The multitude of in-plane shear tests existing in the literature seems to demonstrate the complexity of developing a test adapted to all experimental works. In a general framework of investigation of translaminar cracks in thin laminates, a test able to reproduce a pure in-plane shear loading was required. The laminate studied is notably employed as helicopter blade skin, and cyclic torsion induced by aerodynamic load involves cyclic in-plane shear. This particular application established some specifications for the test needed to carry out this study. To comply with them, an original technological solution has been developed from a three-rail shear test apparatus. This paper describes the resulting “reversible rail shear test” solution and its application to the study of in-plane shear behavior of a thin glass-epoxy laminate. The results concern plain and notched coupons under quasi-static loading, and crack growth tests under cyclic loading.