Experiences with and Prospects for Dynamic Mechanical Testing of Aircraft Structures.

Abstract

Spacecraft structures are subjected to severe environmental mechanical loads, especially during the launch phase. By means of flight load analysis using a dynamic mathematical model spacecraft have to be qualified to withstand all load events occurring during this phase. To verify the mathematical model of the spacecraft, system identification by means of experimental mechanical testing is a prerequisite. One of the most powerful methods for experimental system identification is the modal survey test based on the phase resresonance method. The paper describes the features of the DLR modal survey test facility with special emphasis on applications, experiences and improvements in the testing of current spacecraft structures. A second important field of mechanical testing is qualification testing by realistic simulation of the flight loads. Current trends in the development of multi-axis vibration simulation systems are reviewed.