This paper discusses the through-thickness tensile stresses generated in curved laminates by bending moments. A simple method is derived for calculating these stresses from the applied moments and local curvatures. Comparison with classical elasticity for cylindrical shells showed the errors to be small for most geometries of practical interest. A transition between delamination and flexural failure is predicted to occur at a critical h/R value. The model was used to determine the through-thickness direct stresses in filament-wound cylindrical rings (in both the open and closed configurations) subjected to opening forces. Test results on rings, both hoop-wound and with a ±55° winding angle gave delamination strength values in agreement with results quoted elsewhere. They also showed the predicted transition in behaviour with changing h/R. Some caution is needed when interpreting the failure mode from the appearance of the fracture, since curved samples failed in flexure can also exhibit delamination.
|Number of pages||8|
|Journal||Plastics, Rubber and Composites Processing and Applications|
|Publication status||Published - 1 Jan 1993|