直板叶片冲击振动响应试验的动力学相似设计方法

Dynamic Similarity Design Method for Vibration Response of Impact Test of Straight Blades

针对直板叶片受冲击载荷激励瞬态响应难以预测的问题,提出一种冲击载荷作用下的虚拟模态能量相似方法(Similitude based on virtual mode and statistical energy, SVMSE)。采用统计能量分析、虚拟模态综合法和动力学相似理论相结合的方法,推导直板叶片在冲击载荷作用下时域和频域的响应相似关系,并通过设计实例,采用数值仿真验证所提出SVMSE动力学相似设计方法的有效性和正确性,结果显示,预测的加速度时域响应基本与原型结果保持一致,冲击响应谱的预测误差小于2dB。此外,试验结果表明直板叶片的加速度时域响应与仿真结果一致,冲击响应谱在整个分析频段内误差小于6 dB。因此,SVMSE相似设计方法能够预测直板叶片的冲击响应,为航空发动机直板叶片受高频冲击载荷的模型试验研究提供理论基础。

Aiming at the problem that it is difficult to predict the transient response under impact load, this paper proposed a similarity design method(SVMSE). Combined statistical energy analysis, Virtual mode synthesis and simulation and similarity theory, the similarity relationships are deduced about the acceleration response of the straight blade in the time and frequency domain. The effectiveness of the similitude design approach is validated by using the numerical simulation method in a designed example. The results show that the predicted acceleration response in time domain is basically consistent with the prototype results, and the prediction error of the shock response spectrum is less than 2 dB. Comparing with the experimental results, the acceleration response of straight blade and the experimental results are basically identical, the error of shock response spectrum throughout the analysis frequency is less than 6 dB. Therefore, the SVMSE similarity design method can predict the prototype’s shock response, providing fundamental basis for the model test research of the high frequency impact load on the straight blade of the aero-engine.