A Feasibility Study of the Launcher Simulator with Using Real-Time Sub-Structure Testing Methods

Abstract

The Real-Time Sub-Structure testing method is an attractive concept for dynamic testing of structures. This method does not require an entire system on the test. The specimen tested by a shaking table is its sub-structure, and the main structure is simulated on a computer calculating interactions between main- and sub-structures and generating command signals to control the table on real-time. One possible application for space structures is vibration testing for evaluation of structural dynamic characteristics of a payload mounted in a launch vehicle. Because dynamics of the launch vehicle is simulated on the computer, realistic vibration environment of the payload can be realized on the test and its dynamical response can be estimated with high accuracy. This paper investigates feasibilities for such utilization as "the Launcher Simulator". Transient loads of lift-off are obtained by two algorithms. Numerical results are compared with an exact solution, and characteristics of the algorithms are discussed. A unique problem is existence of rigid body modes of the launch vehicle, and treatment of them is investigated.