Long Term, High Throughput Operation of a Controlled Detonation Chamber Based on Shakedown Under Initial Overload in the Plastic Range

Abstract

Hydrostatic or pneumatic overpressure testing prior to actual service provides a number of purposes related to structural integrity of pressure vessels, including some degree of confirmation of both the design and fabrication processes. For detonation chambers designed to control impulsive pressure loadings, preservice hydrostatic testing at impulses greater than those expected during normal operation can provide an added benefit—the ability to reduce cyclic fatigue damage caused by longterm, highthroughput operation, where the chamber may be use to control hundreds or even thousands of detonations without compromising structural integrity through excessive fatigue crack initiation and growth. This paper illustrates the favorable characteristics of controlled detonation chamber operation following an initial preservice impulsive overtesting program that demonstrates shakedown and satisfaction of strain ratcheting criteria, leading to favorable cyclic fatigue behavior during subsequent longterm, highthroughput operation.