On the operational modal analysis of solid rocket motors

Abstract

ESA's new small launcher - VEGA - has been designed as a single body launcher with three solid rocket motor stages and an additional liquid propulsion upper module used for attitude and orbit control, and satellite release. In order to verify the performance of the solid rocket motors, all of the motors are tested in static firing tests on a test bench. In the frame of the correlation of the solid rocket motor mathematical models, an operational modal analysis tool was developed that is based on the Least Squares Complex Exponential method. The tool allows the computation of experimental poles and modeshapes from the accelerometer data recorded during a firing test. Convergence can be verified by means of the classical stabilization diagram and by the reconstruction of the correlation functions on the basis of the stable poles. ©2010 Society for Experimental Mechanics Inc.