【摘要】 应用小波变换及自助理论对多自由度系统进行模态参数辨识。通过对结构系统响应信号进行小波变换将其表示在时频域内,在分析了小波变换的时频分辨率特性后,利用最小Shannon熵获取最优小波参数,并运用自助理论估计出模态参数分布的置信区间范围。数值仿真表明了该方法对模态参数估计的有效性。将所提方法应用于一个振动台的模态分析,实验结果表明,提出的小波自助模态参数辨识方法降低了模态参数辨识的难度,提高了模态频率和阻尼比的辨识精度。更多还原

【Abstract】 A new method of parameters identification based on wavelet transform and bootstrap theory was proposed to identify modal parameters of multiple-DOF system.With modified Morlet continuous wavelet transform,measured responses were represented in time-frequency domain,then the time and frequency resolutions were analyzed.The option parameters of wavelet function were selected by Shannon entropy and the confidence intervals of the statistical distribution of modal parameters were estimated by bootstrap theory.A simulation and an experiment were carried out on a vibration platform to validate the effectiveness of the proposed method.更多还原