Crack Extension Analysis of Atmospheric Stress Corrosion Based on Peridynamics

Abstract

Based on peridynamics, an atmospheric stress corrosion model was proposed. In this model, the role of hydrogen and stress in anodic-dissolution-dominated stress corrosion cracking was considered, and atmospheric corrosion was characterized by the change in liquid film thickness on the metal surface in the atmospheric environment. The near-field kinetic anodic dissolution model and the atmospheric corrosion model were coupled by varying the liquid film thickness. The thickness of the liquid film depended on factors such as the temperature, relative humidity, and hygroscopic salts. We validated the model using stress corrosion behavior from the literature for 304 stainless steel in a simulated atmospheric environment. The results of the model captured the crack expansion process. The obtained crack expansion direction and branching behavior agreed well with the experimental results in the literature.

Investigation of Crack Propagation and Failure of Liquid-Filled Cylindrical Shells Damaged in High-Pressure Environments

“…The black solid curve represents the expanding crack; the white area is the ordinary continuous unit; the orange area is the crack unit; and the red area is the crack tip unit. Based on this, the displacement field expression of the extended finite element method for the crack extension problem can be further rewritten [45]: In the above equation, Further, the displacement field anywhere in the solution domain of the crack extension problem can be expressed as [46]:…”