If hydrogen is to be used as a commercial source of energy in the future, it is essential to achieve maximum possible specific energy density in the storage and distribution system. This is achieved by compressing gaseous hydrogen. Maximum pressures up to 70 MPa are already attained in fuel tanks. Even higher pressures are found in the compressors and connecting pipes used primarily in hydrogen infrastructure. Components used in this field are exposed to the effects of hydrogen, in addition to temperature and pressure stresses. To ensure safe, reliable operation components must be adequately dimensioned and the necessary specifications determined. For this MPA Stuttgart uses a special ZwickRoell testing system. An HA-series servo-hydraulic testing machine
(Fmax 100 kN) has been fitted with a hydrogen container designed for pressures up to 100 MPa. Tests can be performed in this vessel in a temperature range from -85°C to +150°C. The testing system is used for quasi-static tensile tests, fatigue tests and fracture mechanics tests; hydrogen and reference media are used. Peripheral equipment includes a compressor for the hydrogen, a sophisticated cooling system and a heating unit. "The system in this form is unique and in terms of performance is among the top systems worldwide. The material behavior data obtained is an essential component of our research activities," states Dipl.-Ing Stefan Zickler, Project Manager at MPA Stuttgart.