高速电梯系统时变动力学模型与分析

以往关于电梯系统的研究指出，引起电梯系统振动的主要原因在于外部激励－由曳引机，承重装置，拖动和控制系统等引起。这是基于经典的结构共振理论得出的结论，但不能解释某些电梯的振动行为。本文从时变结构力学的观点出发，计及电梯曳引钢丝绳的长度随时间变化，建立起电梯系统的变刚度动力学模型，采用解析方法给出了高速电梯弹性振动的位移和加速度响应表达式。从理论上证明作为时变系统的电梯，具有振荡运动的特征，存在由变刚度引起的自激振动。进一步研究表明，电梯提速意味着曳引钢丝绳的初始扰动增大，导致电梯振动的加速度也增大，对电梯的舒适性有负面影响。

Modeling and Analysis of Time-varying Dynamics for High-speed Elevator

Previous studies on the elevator system point out the main causes arousing the elevator system vibration, which are the external excitations created by the traction machine, supporting devices drive and control system. This result is obtained by using classical resonance theory of structures, but it cannot explain some vibration behavior of the elevator. In the view of time-varying structure mechanics, a dynamic model with variable stiffness for the elevator system was presented by taking account for the length variation of the traction steel cable in this paper. The expressions for dynamic responses of elastic displacement and acceleration were provided by analytical method. Theoretically, it is proved that the time-varying elevator system has the character of oscillation, in which there exists a kind of self-excitation vibration induced by time-varying stiffness. Further investigations show that the high moving speed of the elevator depends on the large initial disturbance of the elastic steel cable. This results in large vibration acceleration and has a negative influence on the feeling of passengers.