Failure Processes in Filament Wound GRP Pipe

Failure of laminates is described in terms of the fracture of the constituent laminae with particular reference to GRP pipe. The information required to characterise the properties of the laminae is considered and the methods of relating the applied loads on the laminates to the laminae stresses is introduced. Examples of the inter-relation between laminae failure and the properties of laminates are given with reference to the effect of winding angle on the burst and weepage stresses of filament wound tubes and also to strain corrosion of pipe sections in hydrochloric acid.

The purpose of this paper is to emphasise the importance of the properties of the individual layers or laminae on the properties and performance characteristics of laminated structures. Although the examples are restricted to helically wound GRP pipes the main ideas apply to all laminated structures and are particularly relevant to laminates in which the laminae show large degrees of anisotropy.