力限条件设计复杂二自由度法及试验研究
Complex Two-degree-of-freedom Method and Testing Investigation for Force limited Specification

在航天产品振动环境试验中，传统加速度单控的方法存在较严重的过试验现象，力限技术采用力与加速度双控能较好地减轻过试验。获取合理的力限试验条件是力限振动试验的基础。阐明了力限试验减轻过试验的机理，获取力限条件的复杂二自由度法的原理及存在的一些问题。结合复杂二自由度法设计模型并进行了试验，试验中输入加速度在试验件振动方向的前两阶主模态频率处分别下凹约19.5 dB、17.2 dB，证明力限试验条件更接近真实环境。
Among the vibration tests of spacecraft, the acceleration is usually the only specification in traditional test method which generally results in overtesting problem. The force limiting can solve this problem well by dual control of the acceleration and force. Force specification is the foundation of the force limited vibration test. The principle of complex two-degree-of-freedom method and its process to get the force specification are derived in detail. A test verification is designed, and the input acceleration decreased about 19.5 dB and 17.2 dB at the first resonance frequencies of the test item. The test result demonstrates that the specification of force limited test is closer to the reality than traditional acceleration test