PROPERTIES OF MATERIALS IN HIGH PRESSURE HYDROGEN AT CRYOGENIC, ROOM, AND ELEVATED TEMPERATURES

摘要

All testing was conducted on solid specimens exposed to external gaseous pressure. Specific mechanical properties determined and the testing methods used are summarized below:nHigh-Cycle Fatigue - High-cycle fatigue life was established by load (stress) controlled tension-tension testing using smooth specimens and servo-actuated, closed-loop machine.nLow-Cycle Fatigue - Low-cycle fatigue life was established by constant total strain testing using smooth specimens and closed loop testing machine.nFracture Mechanics - Fracture toughness, threshold stress intensity, and cyclic stress intensity were determined using center-notched, fatlgue-precracked, plate specimens or single-edged, notched, fatlgue-precracked, compact tensile specimens.nCreep-Rupture - Creep rate and time to failure were determined using smooth specimens and a standard creep-rupture machine equipped with a recording extensometer.nTensile - Smooth and notched tensile tests were conducted on solid specimens using ASTM tensile testing techniques.