基于Duffing-Holmes系统的材料非线性的量化检测方法

A quantitative detection method for material nonlinearity based on the Duffing-Holmes system

针对非线性Lamb波在材料特性检测中对噪声的敏感性,提出基于Duffing-Holmes系统的材料非线性检测方法。该方法确定Duffing-Holmes系统临界策动力调整Duffing-Holmes系统进入临界状态,并将待测信号经延拓滤波再等比放缩后作为系统扰动输入,建立信号放缩系数与动力学特征指数——Lyapunov指数——之间的线性模型。通过参考信号的Lyapunov指数与线性模型联立求解,实现在噪声干扰下对材料非线性系数的准确检测。经试验证明,该方法有效提高了材料非线性指数的抗噪能力与非线性Lamb的检测范围。

Aiming at the sensitivity of nonlinear Lamb wave to the detection of material properties,a nonlinear detection method based on the Duffing-Holmes system was proposed.First,the critical parameters of the Duffing-Holmes system were determined and the Duffing-Holmes system was adjusted to a critical state,then after being extended and filtered,the signal to be tested was adjusted and scaled as a disturbance input of the system.At last,a linear model between signal scaling coefficient and Lyapunov exponent was established.Lyapunov exponent of the reference signal and the linear model were used to achieve optimal estimation of the real amplitude in the presence of noise interference.Experimental results show that the method can effectively improve the noise immunity and nonlinear Lamb detection range of material nonlinear index.