力控振动试验与过试验现象分析

ANALYSIS OF A VIBRATION OVERTEST PROBLEM AND A FORCE-LIMITED CONTROL VIBRATION TEST

传统的卫星加速度控制试验是根据特定的加速度规范,测量并控制振动台台面的加速度,由这种试验方法做出的估计往往过于保守,会在试件结构的固有频率处产生过试验现象,对结构造成过响应的危害。力控试验是测量并控制卫星结构与振动台台面之间的界面力,这种试验方法能够有效地改善由加速度控制试验造成的过试验现象。本文在传统加速度控制试验产生过试验的原因和力控试验方法的过试验补偿原理的分析的基础上,进一步提出了双控试验这一方法,即同时测量并控制界面力与台面加速度,并且可以更好地模拟真实发射过程中的卫星结构的动力学环境。本文通过数值仿真算例,验证了力控试验对过试验现象具有明显的改善效果,以及双控试验是最为理想的卫星动力学环境试验方法。为力控和双控试验方法真正应用于我国卫星动力学振动试验提供了理论依据。

The traditional vibration test methodology is to measure and control the interface-enviromment of a testing article to a specification.This method is too conservative,it may induce excessive vibration responses at the hardware resonant frequencies,and harm the testing structure.A force-limited vibration test is to measure and control the interface force between the testing article and the shaker to a specification,it can effectively reduce the over-test problem caused by traditional vibration test.The reason for the over-test problem of the traditional vibration test and the principle of over-test compensation of the force-limited vibration test are analyzed.A double control vibration test is put forward,it is to measure and control the interface force and the acceleration of the shacker simultaneously.This method can better simulate the real dynamic environment of the test item.The effect of the force-limited vibration test on the over-test problem is verified by means of numerical calculation.It is also verified that the double control vibration test is the better ideal method to simulate the interface dynamic environment of satellites and rockets.This study provides a theory for application of the force-limited vibration test and the double control vibration test is the better ideal method to simulate the interface dynamic environment of satellites and rockets.This study provides a theory for application of the force-limited vibration test and the double control vibration test in satellite dynamic vibration tests.