Obtaining normal mode parameters from modal survey tests

Spacecraft structures are designed to fulfill various tasks and must therefore be qualified for these tasks. From the point of view of structural dynamics, it is to be proved that the structures will withstand the vibrations due to impulses and shocks during launch and mission and to guarantee that certain prescribed values of acceleration will not be exceeded to protect measuring instruments and sensors. The knowledge of the normal mode parameters is a suitable basis to solve these problems of structural dynamics. In the second part it was shown that the normal mode parameters of aircraft and spacecraft structures can be measured in an acceptable period and through moderate effort using the classical phase resonance method. Additional improvement may be possible by advanced modal survey test (MST) methods.