【摘要】 提出了一个基于小波变换的方法用于非线性结构系统识别。采用复Morlet小波,对非线性结构自由响应信号进行连续小波变换,根据小波系数模极大值的方法提取小波变换的脊线和小波骨架。提取的小波脊线和小波骨架被用来识别结构的瞬时频率和振幅,得到非线性结构的骨架曲线。为降低噪声的影响,采用一个基于奇异值分解(SVD)的方法对识别的结构进行处理。最后通过一个具有非线性刚度结构的数值模拟验证了该方法的有效性。更多还原

【Abstract】 A method based on wavelet transformation for identifying a nonlinear structure system was presented.With it complex Morlet wavelet was adopted and continuous wavelet transformation on a free response signal of a nonlinear structure was performed.According to maximum value of modulus of wavelet coefficient,wavelet ridges and wavelet skeleton were extracted,which could be used to identify the instantaneous frequency and amplitude of the signal,then the skeleton curve of the nonlinear structure was obtained.In addition,a method based on singular value decomposition(SVD) was proceed to deal with the obtained result for dropping influence of noise.At last,the effectiveness of the proposed method was validated via numerical simulation of two structure models with nonlinear stiffness.更多还原