典型机载设备加速振动试验应用方法研究

Application of Accelerated Vibration Test for Typical Airborne Equipment

目的为了提高加速振动试验方法在高新军用装备中工程化应用的准确性和可操作性。方法由于在合理的加速等级下,较大的振动能量可能导致试件局部振动疲劳累积损伤机理发生改变,因此在传统加速振动试验中充分评估结构试件的频率响应特性,得出一种修正的加速振动试验方法。首先结合计算机辅助分析手段对试件进行模态分析及频率响应分析,识别试件的薄弱部位。其次利用结构动力学特性测试手段,对薄弱部位的实测动态特性进行分析,并对超出加速响应限的加速度幅值进行修正。结果以典型的机载设备结构作为研究对象,将试件薄弱部位的频率响应幅值控制在合理的放大系数范围内,保证加速破坏机理的一致性,修改后加速振动试验结果与长周期正常等级振动试验结果特征一致。结论该方法符合国军标中振动试验方法的有关规定,可在装备研制过程中对设备结构部件的加速振动试验加以工程化应用。

Objective To improve accuracy and operability of accelerated vibration test method in high-tech military equipment. Methods Under the reasonable acceleration level, large vibration energy may change the mechanism of local vibration fatigue cumulative damage; so a modified acceleration vibration test method was obtained after fully evaluation of the structural response of frequency response characteristics in traditional accelerated vibration test. Firstly, modal analysis and frequency response analysis of specimen were carried out by means of CAE to identify weak parts of the specimen. Secondly, dynamic characteristics of weak parts were analyzed by the structural dynamic characteristic test method. And the acceleration amplitude exceeding the acceleration response limit was corrected. Results With the typical airborne equipment structure as the research object, the frequency response amplitude of weak parts of specimen was controlled within the reasonable range of amplification coefficient. The consistency of the accelerated failure mechanism was ensured. After the modification, the result of acceleration vibration test and long period normal level vibration test were consistent. Conclusion The method is consistent with relevant provisions of the national military standard. The engineering applications are suggested in accelerated vibration test, which is limited to the structural components in the equipment development process.