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。为降低噪音的影响，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。

A method based on wavelet transform for identifying nonlinear structure system is presented. The method employs complex Morlet wavelet, and perform continuous wavelet transform on free respond signal of a nonlinear structure. According to maximum value of modulus of wavelet coefficient, the wavelet ridges and wavelet skeleton are extracted, which can be used to identified instantaneous frequency and amplitude of signal, then the skeleton curve of nonlinear structure is obtain. In additional, a method based on singular value decomposition (SVD) is proposed to proceed the obtained result for decrease the influence of noise. At last, the effectiveness and accuracy of the addressed method are validated via a numerical simulation of structure model with cubic nonlinear stiffness.