Numerical simulation of erosion and fatigue failure the coal gangue paste filling caused to pumping pipes

•Porosity model, CFD-DEM method, DEM-FEM, the erosion fatigue, pumping gangue. The mechanical behavior of high-viscosity coal gangue paste (CGP) has been studied, while computational fluid dynamics and discrete element coupling method (DEM-CFD) was employed for it. Through the bidirectional coupling of particles and fluid, the force among different particles in the pipe and the effect of collisions were analyzed. The particle-pipe or particle–wall collision force has been solved by coupling the finite element method with discrete element method (DEM-FEM). The mechanical analysis of pipe’s life is realized, which was based on the fracture and fatigue analysis software NCODE, in which the actual pipe material parameters used in engineering were considered. The numerical simulation results show that the erosion of the flow field in the pipe (inlet and elbow) is serious, and the life of the parts will be greatly shortened. The simulation results agree with the results of field test very well. Hence, this numerical simulation method can be used to simulate the pipe erosion and wear, estimate the pipe’s life, and predict the positions of the failure.