Approximate computing of shock response spectrum using reduced impedance method

This paper presents an approximate computing method of a shock response spectrum induced by a drop-weight shock test. The proposed method is based on a reduced impedance method, and computes the shock response spectrum by synthesizing the vibration characteristics of the spacecraft equipment and shock test device. A computational efficiency of the traditional reduced impedance method is significantly improved by proposing the method to only synthesize the dominated vibration characteristics of the substructures. The shock responses on the simplified model of the drop-weight shock test device are analyzed by the traditional reduced impedance method and the proposed method. Then, the shock response spectra given by both methods are compared. The result shows that the proposed method provides the shock response spectrum with accuracy of ±6dB for the traditional methods, and the computation cost is decreased by 1/60. This study offers a practicable approach to estimate an approximate shock response spectrum before a drop-weight shock test.