一种基于白噪声响应的随机载荷谱识别方法

基于频域内随机振动响应与载荷的关系,根据对结构控制点随机振动响应谱的预设,提出一种新的随机载荷谱简便识别方法。首先计算结构在白噪声载荷谱下,结构控制点处的响应功率谱,即系统的频响函数;然后将控制点的期望输出响应谱与控制点在白噪声载荷谱下的响应谱相比,进而得到相应的随机载荷谱。应用上述方法,借助于有限元仿真软件在设定控制点输出加速度响应谱为梯形谱的条件下,对某典型舱段结构进行基础加速度载荷谱逆向识别与正向检验,证明方法的有效性与准确性。

AnIdentificationMethodofRandomLoadSpectraBasedon FrequencyResponseAnalysisunderWhiteNoiseLoads

In this paper, based on the relationship between frequency response and load within the frequency domain, also assuming the prior knowledge about the frequency response spectrum for random vibration of structural control points, it comes up with a new method in identifying the random load spectrum. At first, we calculate the response power spectrum of structural control points, so-called as system frequency response function, given the white noise load spectrum input. Then comparing the system frequency response function with the desired output response spectrum, we derived the corresponding random load spectrum. Representative finite element analysis (FEA) simulation results are presented and discussed which demonstrated that the method is effective in reversely identifying and inversely correcting the fundamental acceleration load spectrum for a specific cabin structure, if setting the output acceleration response spectrum of the control points to be trapezoidal.