Reliability and Failure Analysis of Jet Vane TVC System

Abstract

Structural and system reliability of a typical jet vane (JV) thrust vector control (TVC) subsystem subjected to stochastic loadings is investigated. Jet vane TVC (JVTVC) is used in many aerospace liquid and solid propulsion systems. For the purpose of this work, JVTVC structural reliability of a solid rocket propulsion system is computed using an explicit closed-form limit state function. The JV structure is influenced by the internal ballistic loads emanating out of the solid rocket propulsion internal ballistic, whose performance is modeled via a one-dimensional uniform flow assumption at the engine steady operating condition. Subsequently, JV structural reliability is predicted using the methods of mean value first-order second-moment as well as the first- and second-order reliability methods. The reliability results of the analytical methods are compared with Monte Carlo simulation for verification purposes. Finally, a comprehensive sensitivity analysis is performed to identify the key JVTVC and solid rocket propulsion design parameters affecting the TVC total system reliability. The parameters considered for sensitivity analysis include the JV geometric and structural properties as well as the solid rocket propulsion ballistic and geometric features. It turned out that the vane support arm radius and the vane area are the most important strength and load design variables, respectively, that impact the JVTVC failure reliability.