基于广义多项式假设模态法的大型螺纹旋风铣削工件系统动力学分析

摘要

This paper takes the supporting system of a large-scale screw whirling as the research object, to study its dynamic response. The screw workpiece supported by chuck, floating rest, hold device, and tail-stock is simplified to a flexible beam with elastic bearings, and the cutting force is assumed to be cyclical "half-sine" excitation signal. The kinetic system equations are derived based on Generalized Polynomial Assumed Mode Method, and are solved by the Runge-Kutta method using Matlab to analysis the effect of stiffness of the floating rests and hold devices. The numerical results show that the deflection of screw significantly decreases due to the existence of hold devices. Contrast the dynamic response of the cutting point in two conditions, having and no hold devices, we can found that when introduced into dynamic hold device, just select small floating rest stiffness can effectively reduce the maximum of dynamic response, and dynamic response of the workpiece is determinated by the inherent characteristics of system and the cutting force.%文章以大型螺纹旋风铣削的工件装夹系统为研究对象,将铣床卡盘、浮动支撑、抱紧装置,以及尾架简化为弹性约束,并将切削力假设为周期性“半正弦”激励信号,运用广义多项式模态假设法,建立了大型旋风铣削工件系统的动力学模型.基于Matlab编程平台,利用Runge-Kutta法对系统的动力学模型进行数值分析,以研究大型螺纹工件的浮动支撑、抱紧装置对螺纹动态响应的影响.分析结果表明:工件的动态响应是由系统固有特性与切削力特性共同决定,而且抱紧装置对工件动态响应影响显著.当引入抱紧装置后,只需选取较小的浮动支撑刚度就能有效的降低切削点处的动态响应.