基于频响比法的多维振动基础激励试验模态分析  

Modal Analysis by Means of Multi-Axis Base Excitation Based on Frequency Response Ratio Method

作　　者：张鹏飞[1] 孙颖 吴家驹[1] 张永亮[1] Zhang Peng-fei;Sun Ying;Wu Jia-ju;Zhang Yong-liang(Beijing Institute of Structure and Environment Engineering,Beijing,100076)

机构地区：[1]北京强度环境研究所,北京100076

出　　处：《导弹与航天运载技术》2020年第5期75-79,共5页Missiles and Space Vehicles

摘　　要：针对多维振动中各个自由度之间的相干影响导致矩阵奇异的问题,提出了基于频响比的传递矩阵估计方法。设计算例和试验对频响比法进行了验证,并与固定基础模态试验结果进行了对比。结果表明基于频响比法的多维振动基础激励试验模态分析有明显优势,频响比法能够获得高质量的传递矩阵,六自由度运动基础激励接近试验件的实际使用环境,基础激励量级的变化明显反映出结构模态频率和阻尼比的非线性特征,该方法对于提高基础激励模态试验精度具有参考价值。Modal characteristics close to working state can be acquired by modal analysis of base excitation based on multi-axis vibration test.Transfer function matrix estimating method based on frequency response ratio is proposed in allusion to the problem that coherence of different degree of freedom induced matrix singularity.Numerical example and experiment is actualized to validate the method of frequency response ratio,and the result is contrasted against that of modal test on fixed foundation.The result shows that modal analysis by means of multi-axis base excitation based on frequency response ratio method has obvious advantages.High quality transfer function matrix can be acquired by the method of frequency response ratio.Six degrees of freedom base vibration is close to the practical working environment.The level of base excitation reflects nonlinear characteristic of frequency and damping ratio.This method has reference value for improving the accuracy of base excitation modal test..

关 键 词：模态试验 多维振动 基础激励 非线性特征 

分 类 号：V448.252[航空宇航科学与技术—飞行器设计]