超小型衛星の衝撃試験レベル調整方法に関するシミュレーション

Abstract

Development of small satellites (50kg or less) is undergoing all over the world. Regardless its size, any satellite has to be tested for space environment. Various environment tests, such as vibration, vacuum, low and high temperature are necessary. Especially, shock test is one of the most difficult tests. The shock test needs to satisfy the SRS (shock response spectrum) requirement imposed by the launcher. If the SRS obtained in the test does not exceed the SRS requirement level, the test is invalid. At the same time, the SRS level as low as possible while satisfying the requirement is desired to protect the satellite from the overstress. SRS obtained by an air-gun type shock machine was analyzed using a commercial finite element code (LS-DYNA) to investigate the SRS at low frequencies, 100 to 300Hz, which is very difficult to control in the actual test. The analysis showed that controlling the friction of the slide table is effective to change the slope of SRS at the low frequencies. The lower the friction, the higher slope of SRS is obtained.