In this paper, the failure of glass-reinforced polyester mortar pipes with different cores subjected to pure and combined loading are analyzed. To enhance the stiffness of fiberreinforced polyester pipe, filler layer is incorporated in between fiber-reinforced polyester plies. Thus, in this study, new nanocomposite materials are proposed as a core layer in the glass-reinforced polyester mortar pipes. The performance of the pipes in the presence of nanosilica/resin, nanosilica/fiberglass/resin and multi-walled carbon nanotubes (MWCNTs)/resin and sand/resin cores are investigated. Finite element method is used to analyze the effects of extensive design parameters on the first ply failure and functional failure of glass-reinforced polyester mortar pipes. Maximum normal stress, Tsai–Wu and Tsai–Hill criteria are employed for the failure analysis. Two end boundary conditions are considered in the simulations. The effects of core material constituents, core thickness, filament winding angle and lay-up configurations, layers thicknesses and pipe radius are investigated. The results are also obtained under pure and combined loading conditions. The stress concentration around circular and rectangular holes in glass-reinforced polyester mortar pipes with sand/resin core is also studied. Accordingly, the stress concentration factors are reported for each case. Detailed discussions are done and brief design guidelines are given.
