Performance Investigation of Superplastic Shape Memory Alloy-Based Vibration Isolator for X-Band Active Small SAR Satellite of S-STEP under Acoustic and Random Vibration Environments

Abstract

In a launch environment, all satellites are subjected to severe random vibration and acoustic loads owing to rocket separation, airflow, and injection/combustion of the fuel. Structural vibrations induced by mechanical loads cause the malfunction of vibration-sensitive components in a satellite, leading to failures during the launch process or an on-orbit mission. Therefore, in this study, a shape memory alloy-based vibration isolator was used on the connection between the launch vehicle and satellite to reduce the vibration transmission to a satellite. The vibration isolator exhibited a high performance in the vibration isolation, owing to the dynamic properties of super-elasticity and high damping. The vibration-reduction performance of the vibration isolator was experimentally verified using random vibration and acoustic tests in a structural thermal model of the satellite developed in the synthetic aperture radar technology experimental project. Owing to the super-elasticity and high attenuation characteristics of the vibration isolator, it was possible to significantly reduce the random vibration of the satellite in the launch environment. Although the mechanical load of the acoustic test mainly excited the antenna on the upper side of the satellite rather than the bottom side, the results of the acoustic test showed the same trend as the random vibration test. From this perspective, the vibration isolator can contribute to saving the costs required for satellite development. These advantages have made it possible to develop satellites according to the new space paradigm, which is a trend in the space industry worldwide.

Keywords

• synthetic aperture radar (SAR)
• small SAR technology experimental project (S-STEP)
• random vibration test
• acoustic test
• shape memory alloy (SMA)
• structural thermal model (STM)