惯性边界下梁的非线性振动分析

本文基于轧制过程中轧辊与带材的振动，将带材简化为Euler梁，轧辊简化成惯性元件，建立了梁在惯性边界下的非线性振动模型，首先根据哈密顿原理建立梁的纵向和横向非线性振动微分方程和惯性边界条件，再利用Kantorovich平均法简化运动方程和边界条件，然后采用修正迭代法求解方程。通过数值计算获得了梁的幅频响应曲线，研究了梁振动的非线性性态的变化规律，并讨论了惯性边界条件下梁的长度、惯性元件的转动惯量对梁的振动频率的影响规律。

Wavelet ridge-based novel method for chaotic motion identification

A novel method is proposed for chaos identification based on the theories of wavelet ridge line and chaos.First,the Lorenz system is applied as the research object and its evolutionary processes from periodic motion to chaotic motion are analyzed systematically.Second,the diagrams of phase trajectory,power spectral density and wavelet ridge line are compared mutually.The comparison results indicate that the motions of period,period-doubling bifurcation and chaos can be obviously distinguished using the wavelet ridge line.Finally,other three typical chaotic systems are studied,the regularity and detail features of chaotic motion reflected in the wavelet ridge line diagrams are summarized.The study results prove that the chaotic motion and the random noise can be distinguished clearly using the wavelet ridge line.