Improvement of resin fracture model for ultimately light design of Type 4 hydrogen tank

Abstract

A conservative design methodology which results in overweight winding of helical layer in Type 4 hydrogen tank has been employed since the rupture phenomena in the vicinity of metallic boss of the tank is too complicated to predict precise burst pressure. The complexity comes from both the meso-scale structure constituted by overlapped carbon fiber bundles and local bending deformation in the part. Authors have developed a meso-scale based methodology for precise prediction of the burst pressure of Type 4 hydrogen tank, where carbon fiber bundles and matrix resin are perfectly distinguished for modeling. We investigate resin fracture model for the improvement of burst pressure prediction initiated by the rupture in the vicinity of metallic boss, assuming the reinforcement by means of Automated CFRP Tape Placement to realize ultimately light design of the tank. Specimens representing meso-scopic structure in the part are manufactured and submitted to the three-point bending tests. Through the validation of meso-scale fracture simulations corresponding to the tests, we demonstrate compressive fracture model of resin is decisive for precise description of terminative fracture phenomena in bending test specimen.

Keywords

• high pressure hydrogen tank
• carbon fiber reinforced plastics
• filament winding
• meso-scale strength model
• finite element analysis