动态载荷激励位置时域识别技术研究

Time-domain identification technology for dynamic load locations

对实测振动加速度信号进行分析,采用基于盖尔圆定理的GDE算法识别作用于结构的动态载荷数量;在此基础上,建立结构有限元模型,运用基于正交多项式拟合的动态载荷时域识别方法拟合虚拟激励位置处的当量动态载荷,基于优化理论建立动态载荷位置时域识别的数学模型,计算该模型结果向量的均方根值并将其作为识别动态载荷激励位置的判别依据,提出了动态载荷激励位置识别的均值判别系数法。仿真和试验结果均表明方法正确可行,可用于线弹性系统多个谐波载荷或任意形式时变动态载荷的激励位置识别。

The actual measured vibration acceleration signals were analyzed and the dynamic load number was identified with GDE algorithm based on Gerschgorin's disk theorem. The structural finite element model was built, then the dynamic load identification method in time-domain based on orthogonal polynomial fitting was used to fit the equivalent dynamic loads at virtual locations. The mathematical model of dynamic load location identification in time-domain was built based on the optimization theory. The root mean square value of the result vector of the model was calculated and taken as a criterion to identify dynamic load locations. The mean value discriminating coefficient method for dynamic load location identification was proposed. Numerical simulation and experimental results showed that the proposed method is correct and feasible to idetntify the locations of multiple harmonic loads or arbitrary time-varying dynamic load.