The chaotic motion of an elastic shaft-disk rotor system including the geometric nonlinearity of the shaft with a transverser crack is investigated. The critical condition for the system to enter chaotic state is given by the Melnikov method. Meanwhile, whether the chaos occurs is determined by the Poiacare map, phase portrait and time-displacement history diagram.

In this paper, the nonlinear dynamic stability of a rotating shaft-disk with a transverse crack is studied, The crack and the disk are located in arbitrary positions of the shaft respectively. Using the equivalent line-spring model, the deflections of the system with a crack are constructed by adding a deflection to the deflections of the uncracked system. The unstable regions are confirmed by Runge Kutta method and the Floquet theory. The effects of crack depth, crack position, disk position, disk thickness and rotating speed on the principal unstable regions are discussed. The numerical results are compared with available data.

Based on Hamilton's principle and the Timoshenko-Mindlin hypotheses on moderately thiek plates, a set of non-linear governing equations of motion for truncated conical moderately thick shells is sen up in large overall motion. By using the Galerkin method and the harmonic balance method, the problem of non-linear vibration of the truncated conical moderately thick shelts is analzed. The present results are compared with the available data for speciat cases.

The prolem of bearm-plates with as delamiation located at an arbitrary site undergjoing nonlinear free vibration without damp is investigated, For this problem. Noalinear govning equations a well as the contiunity. Equilibrium and compaibility conditions are esablished. The Galerkin method and harmorie balance method are employed to find solutions. Filnslly, in some examples. amplitude-frequeney curves of the deiaminated structure are presented in order to reveal some special dynamic features.

给出了弹性变形体处于非惯性参考系中的运动描述，基于Hamilton原理建立了中厚矩形板在空间运动中的动力学一般方程，应用多尺度法及谐波平衡法具体地分析了简支矩形板在空间运动中的非线性振动问题。