Effects of Production Variations on the Reliability of a Solid Rocket Motor

Abstract

*† ‡ § ** Design changes performed at the later design phases or production phase cause a tremendous increase in cost, therefore reliability which is a design parameter that affects cost, readiness, mission success and safety of a system should be evaluated in early phases. Reliability of a solid propellant rocket motor is typically determined through a series of tests. However, it is not possible to perform large number of tests in early phases in order to determine the reliability and take actions to improve the design. That’s why design changes should be performed according to reliability predictions. In this study, reliability and sensitivity analysis of a solid propellant rocket motor is performed by considering the variations caused by the manufacturing processes and important parameters that should be inspected in production are determined. Since the performance of the rocket motor is influenced by a number of parameters, response surface method is used to predict their effect and Monte Carlo Simulation technique is used to predict the reliability. As a result weak parts of the design and the variations that should be controlled by means of process development are determined.