Damage-tolerance design method for composite high-pressure hydrogen vessels of fuel cell vehicles and stacking-sequence optimization method based on the design method

An approach was proposed to design high-pressure composite hydrogen vessels for fuel cell vehicles with damage tolerance. In addition, a stacking-sequence optimization method was developed, which was built upon the damage tolerance design. A no-growth approach, damage categorization, and residual strength requirements were proposed for the damage-tolerance design method for high-pressure hydrogen vessels, which were implemented in the damage-tolerance design method for composite aircrafts. The initial burst pressure was set at 180% of normal working pressure (NWP) assuming that the structural health monitoring (SHM) system with acoustic emission (AE) testing would immediately detect the occurrence of fiber failure. Stacking-sequence optimization was then conducted to minimize vessel thickness and meet the residual strength requirements. As a result of the optimization, the calculations confirmed that the vessel thickness could be reduced by approximately 52% of the existing vessel stacking sequence. The results show that the thickness of the vessel can be reduced by introducing a damage-tolerant design. Moreover, the proposed method for an optimal design based on the damage-tolerance design method is effective.