Failure Analysis of the Dome-Cylinder Transition Region of a Pressurized Large-Capacity Type IV Hydrogen Storage Vessel

Type IV hydrogen storage vessel has shown its extraordinary ability in storage and transportation of compressed hydrogen in an efficient and economical way. Past years have witnessed a development trend of increasing storage capacity as well as pressure. Nevertheless, conventional studies usually ignored the complicated stress state and material’s failure behaviors in the dome-cylinder transition region. As a vulnerable part of a large-capacity tank, it is essential to comprehensively understand the mechanical behaviors in the transition for lay-up design. In this work, a finite element model is established considering the designed winding pattern mainly including winding angle, thickness, and lay-up sequence. Both intralaminar and interlaminar failure modes of wound composite layers are taken into account. Cohesive elements are inserted between adjacent layers. Initiation and evolution of composite failure induced by high stresses in the transition region is analyzed in details from several aspects. Effects of discontinuities from local deformation, hoop ply terminations and property discrepancies between composite layers are investigated respectively. Interestingly, the simulation presents a limited failure zone. The influence on the burst pressure and burst mode is also discussed based on local stress redistribution due to delamination. The results of this work are compared with conventional methods and will provide a reference for designing the large-capacity type IV hydrogen storage vessel.