模拟自由边界对卫星动力学特性的影响

为了研究高精度航天器微振动试验中模拟自由边界附加质量对卫星动力学特性的影响，建立考虑附加质量的卫星地面微振动试验模拟自由边界理论模型，与卫星结构动力学模型仿真结合，分析附加质量对卫星模态频率和频率响应的影响规律。在此基础上，以施加不同附加质量的卫星结构模拟试验件为实验对象，测试验证了附加质量对卫星结构动力学特性的影响。结果表明，附加质量对结构模态频率和频率响应产生明显影响，附加质量越大，对卫星动力学特性影响越大，且对频率响应峰值的影响更加突出。据此，提出附加质量应控制在卫星总质量的5%以内，以避免其在地面微振动试验中给卫星的动力学特性及微振动响应带来严重影响。

Effect of simulated free boundary on dynamic characteristics of satellite

To study the effect of the attached mass of the simulated free boundary on the dynamic characteristics of a high-resolution satellite during the ground micro-vibration test, the theoretical model of the free boundary is established with consideration of the attached mass in the satellite underground micro-vibration test. The effect of the attached mass on the modal frequencies and the frequency response is analyzed by combining this theoretical model with the structural dynamics model of a satellite. Furthermore, the dynamic test is carried out for a structural satellite model with different values of the attached mass, and the test result is analyzed. It is shown that the ratio of the attached mass has a significant influence on the modal frequency and, especially, on the frequency response peak. Thus, the attached mass should be controlled within 5% of the total mass of the satellite, to avoid the serious negative influence on the dynamic characteristics of the satellite in the micro-vibration test.