Numerical simulation of thermal stress and life assessment of a thin double-layer metal hydride bed under combined thermal and mechanical loads

In this work, the finite element model of the hydrogen absorption process in the thin double-layered metal hydride bed (MHB) has been established. The Johnson–Cook constitutive model, considering the temperature softening and strain rate hardening effect, was used to simulate the mechanical behavior of 316L stainless steel during the hydrogen absorption and desorption processes. The simulation results agree well with the experimental results, which verifies the effectiveness of the numerical model. The equivalent stress distribution of the stainless steel bed in the process of hydrogen absorption and desorption has been calculated by the aforementioned model. The influence of the defect depth and opening angle on tank safety has been calculated and analyzed considering the possible defects in the welding process and service life. Finally, according to the American Society of Mechanical Engineers boiler and pressure vessel code criterion, the fatigue–creep interaction condition of the MHB was predicted and analyzed. This work can provide an effective reference for the design of a hydrogen storage bed.