A method for assessing the stress-strain state of shell structural elements under load in a hydrogen environment

A method for assessing the stress-strain state in cylindrical shells was developed, taking into account the effect of external force loads and the influence of absorbed hydrogen. This influence promotes an increase in internal damage to the metal and a significant rise in the concentration of absorbed hydrogen, leading to the overall embrittlement of the metal. As a result of reduction of the specific fracture energy the material damage resistance decreases. The finite element method and the digital image correlation method was employed to analyze the distribution of axial, tangential, and radial stresses in the walls of cylindrical shells, as well as their effect on the overall deformability of the structures. Special attention was paid to the influence of prior material deformation and hydrogen degradation on the material resistance to fracture. The results showed that hydrogenation could significantly reduce critical strain, accelerating the fracture process, especially at high hydrogen concentration. Pri-strain plastic deformation contributes to an increase in internal damage in the metal and a substantial rise in the concentration of absorbed hydrogen, leading to the overall embrittlement of the metal and the specific fracture energy decrease.