Traditional vibration tests based on acceleration response control are intended to control the acceleration of shaker platform according to specified acceleration specification. This kind of control may sometimes lead to over testing phenomenon at the natural frequency of testing article. Force limited vibration test is able to mitigate that tendency. Detailed calculations for force limitation specification were presented on the basis of the model of simple two-degree-of-freedom system (TDFS). Furthermore, the spectra of force and acceleration between spacecraft bracket and shaker platform were derived. Then the force limited random vibration test and force limited sine vibration test were carried out for spacecraft bracket. Experimental results indicate that the force limited vibration test in terms of force spectrum derived from the simple TDFS model can simulate the realistic dynamic environment better than the conventional acceleration response control vibration test, and the over testing tendency can be alleviated effectively. Thus those results offer a good verification for spacecraft vibration test.%传统航天器加速度响应控制振动试验是根据特定的加速度规范,控制振动台台面加速度,这种试验方法会在试件固有频率处产生过试验现象,力限振动试验可以有效地缓解这种过试验.基于简单二自由度模型给出了详细计算力限条件的方法,在此方法基础上,推导出了航天器试件支架与振动台台面间力谱和加速度谱,并对试件支架进行力限正弦振动试验和力限随机振动试验,实验结果表明:与传统加速度响应控制方法相比,基于简单二自由度模型力谱条件的力限振动控制试验能够更加真实模拟动力学环境,有效缓解振动过试验,可以为航天器振动试验提供很好的试验依据.
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