Finite element method assisted stiffness design procedure for non-circular profile composite wastewater pipe linings

The elastic behaviour of filament wound egg shape profile glass/polyester composite wastewater pipe linings was analysed with the scope of developing a simple stiffness sizing method. Ring compression tests were executed and simulated with the finite element (FE) method to verify the modelling concept. Good agreement has been confirmed, and a more realistic pipe-in-pipe type model was developed to simulate the operational loads and deformations of the liner pipes. Using the FE model outputs a 10 parameter function of the three most important material and geometric parameters was fitted to describe the defined stiffness of specific pipe cross sections. A unique design chart was developed representing the deformations of given cross section liner pipes of a wide range of stiffness values in function of the applied outer pressure.