Mechanical shock machine

Abstract

A mechanical shock machine may consist of a small bench-top device with a built-in pneumatic isolator, the working parts of which are enclosed to prevent injury to the operator. The device to be tested is placed on the test platen of the mechanical shock machine and retained there by mechanical clamps or by a viscous fluid. A bullet-like object is then accelerated toward the underside of the test platen, striking it in free or ballistic flight. The strike target contains a resilient pad. Different thicknesses of this pad produce different durations of the shock pulse, with thicker pads relating to longer duration pulses. A skirt near the outer edge of the test platen is suspended in a viscous shock fluid that absorbs the energy of the bullet strike without a major displacement of the test platen, and reduces second strike effects and ringing of the assembly. The motor inducing acceleration to the bullet is contained and its motion captured within the enclosed volume of the shock machine. The bullet is captured after it has expended most of its energy to the platen assembly by a guard ring and snubber. Return of the motor, bullet and platen to their initial position before initiation of the shock pulse may be by powered reversal or by gravity, or a combination thereof.