Simulation of Multi-Axis Vibration in the Qualification Process of Space Structures.

The environmental loads acting as mechanical vibrations on a space structure are merely of transient nature and are concentrated on the low frequency range. Today, however, the standard testing procedures are based on single-axis excitation with sine sweep or random excitation signals. Newer qualification concepts which comprise multi-axis base excitation and transient load simulation are discussed in this paper. To realise such concepts, multi-axis vibration test facilities are required. A hydraulic prototype test facility, primarily designed for research and development, is presented. Its operating costs are comparatively low, and only smaller structures up to a mass of 3000 kg can be handled. Topics and open problems concerning the multi-axis vibration test technology are pointed out. System identification of elastomechanical structures under base excitation is considered. Furthermore, prospective work concerning the improvement and refinement of multi-axis transient vibration testing is discussed