Carrying capacity and deformation properties of glass-reinforced plastic pipes of various construction

Glass-reinforced plastic pipe under internal hydrostatic pressure starts to “sweat” at loads lower than the mechanical strength of the material. It is established that the life of such pipes is well described by an exponential law. The leakage mechanism is mainly controlled by the deformation properties of the reinforcement and resin. The period of reliable service can be estimated from the time of development of the strain corresponding to the end of the phase of steady-state creep. It is shown that for pipe made with cross-wound glass rovings, the winding angle and the number of roving ends have a considerable influence on the creep and life.