Experimental measurement of diaphragm deformation and bursting in a two-stage light gas gun

The burst process of steel diaphragms that are used in two-stage light gas guns to seal the pump tube from launch tube was investigated. Four experiments were performed, in which diaphragm surface velocity and the pressure acting upon the diaphragm were measured during standard gun cycles without projectile or sabot. The measurements indicate that shocks are travelling inside the pump tube, tearing the diaphragm open when the pressure is high enough. The diaphragms investigated burst at a pressure between 30 and 37 MPa. The pressure signals obtained are superposed by considerable noise. The two major contributors to this noise are identified as (1) natural oscillation of the pressure sensor and (2) standing sound waves in the pressure sensor drill hole, both excited by the shocks travelling along the pump tube.