卫星结构单轴与多轴正弦振动试验技术

Research on single-axis and multi-axis sinusoidal vibration tests of satellite structure

卫星真实的动力学环境载荷往往是多轴向同时发生的,当前3个方向单轴振动试验是一种非真实的近似等效试验,并不能完全模拟卫星真实的发射环境,存在失真缺陷。该文采用多轴振动试验技术可以有效地降低复杂结构在试验过程中的“过试验”和“欠试验”。该文开展卫星结构多轴振动试验技术研究,应用多输入多输出控制方法,进行小量级单轴振动与三轴同振试验,获得某卫星结构单轴和多轴振动时频响应数据,分析单轴与三轴同振对结构响应的影响。多轴振动更容易激发产品在不同方向的结构模态,多轴振动条件下,结构在3个方向的共振频率均比单轴振动时偏低;三轴同时加载比单轴单独加载所产生的等效应力响应最大值要更大。

The real dynamic environmental load acted on a satellite is in multiple axes,and the current single-axis vibration test in three directions is an approximate equivalent test,which cannot completely simulate the real launch environment of the satellite,and it has distortion defects.Multi-axis vibration test technology can effectively reduce the“over-test”and“under-test”of complex structures in the vibration test.In this paper,satellite structure multi-axis vibration test technology is introduced,and the multi-import and multi-export(MIMO)control method is utilized.Based on the small-scale single-axis and triaxial vibration tests,the time-frequency response data of a satellite structure is obtained,and the uniaxial and triaxial vibration on structural response is analysed.The structural modes of the product in different directions can be easily excited by multi-axis vibration.Under the multi-axis vibration conditions,the resonance frequencies of the structure in three directions are lower than that when single-axis vibration is applied.The maximum equivalent stress response produced by triaxial loading is larger than that produced by uniaxial loading.