Fatigue Life Assessment of High-Pressure Hydrogen Storage Vessel Enhanced by Crack Grinding

Abstract Fatigue life of high-pressure hydrogen storage vessel with design pressure of 45 MPa and 99.9 MPa was investigated. The feasibility of improving fatigue life with crack grinding strategy was verified. First, fatigue assessment with fracture mechanics and S–N curve method was performed. The result indicates crack grinding is beneficial to the fatigue life of cracked hydrogen storage vessel. Then, slow strain rate tensile test of 4130X steel in 100 MPa hydrogen environment was performed. A fracture criterion that maximum principal stress equals the ultimate strength of 4130X was suggested for failure in 100 MPa hydrogen environment. At last, numerical burst pressure simulation was performed. The results suggested that burst pressure of hydrogen storage vessel with grinding groove was not influenced by crack grinding. The outcome of this work suggests a grinding strategy that repairs immediately upon crack detection for hydrogen storage vessel.