含轴裂纹甘蔗切割器系统非线性动力学特性分析!

Nonlinear Dynamic Characteristics of Sugarcane Cutter System with Cracked Shaft

将切割器简化成铅垂悬臂转子-支承系统,将斜裂纹设置在轴与盘身连接处附近,考虑裂纹与切割力2种非线性因素建立了该系统的3自由度动力学方程。基于该模型,选用开斜裂纹刚度计算模型,对含斜裂纹的甘蔗切割器动力特性进行数值计算与分析。结果表明,系统在含裂纹与无裂纹时相比刀盘轴心轨迹及其频率成分有显著不同;刀盘轴转速为800 r/min时,随裂纹深度增加,轴心轨迹形状变化较大,对应的进动幅值呈递增趋势。

The cutter was simplified to a vertical over-hung rotor-bearing system.The slant crack was set near the junction of shaft and disk,only considering two nonlinear factors:the slant crack and the nonlinear cutting force.3-DOF dynamic equations of the system were founded.Based on this model,a stiffness calculation model of opening slant crack was chosen and the dynamic characteristics of slant cracked cutter were investigated by numerical simulation.The results showed that,when the system was under the action of crack,the orbit of the shaft center and frequency components of the cutter were significantly different from that without the crack.When n was 800 r/min,as the crack depth increased,the shapes of orbit of the shaft center varied comparatively great and the corresponding displacement amplitudes tended to increase.