Mechanical Failure Analysis Of Epoxy Resin Sleeves Under Water Hammer And Pressure Fluctuation

The instantaneous pressure pulsation generated by the water hammer effect can form a rapidly rising stress wave around the epoxy bushing material. These dynamic loads, propagating within the material, can induce localized shear and tensile strain concentrations, particularly around material defects, microcracks, or interfacial discontinuities, potentially leading to crack initiation and propagation. The interaction between this high-frequency, high-amplitude pressure change and the elastic modulus and fracture toughness of the cross-linked structure of the material itself is the main physical basis for the cracking or fracture of epoxy resin bushing in a dynamic environment.

Epoxy resin is a thermosetting polymer, and its fracture toughness is significantly affected by cross-linking density, ambient temperature, and moisture content. Cyclic loading caused by dynamic pressure waves can promote the expansion of micropores and a decrease in interfacial bonding at the microscale. Simultaneously, moisture penetration can plasticize the resin, reducing its crack resistance.