非线性超谐式振动时效装置机理分析

Resrarch on the Mechanisms of the Novel VSR Devices with Nonlinear Superharmonic Vibration

振动时效是消除工件残余应力的一种有效手段,具有无污染、效率高,节约时间、能源和费用等特点。在使用过程中对于轧辊等这一类低阶固有频率高于现行激振器激振频率的高刚度工件,常规振动时效的激振频率无法接近或达到工件的固有频率,因此无法实现此类高刚度工件的振动时效。针对这个问题,首先,提出了基于非线性动力学的非线性超谐式振动时效方法及装置设计理论,由残余应力的产生和分类分析其对工件力学性能的影响,并从宏观和微观分析得出非线性超谐式振动时效方法消除大刚度工件残余应力的机理,基于机理分析得出该非线性超谐式振动时效方法对激振力、激振频率和时效时间等的工艺要求;其次,提出了对于大刚度工件的动力学简化模型以及非线性超谐式振动时效装置的非线性振动数学模型,使用摄动法和多尺度法研究了该非线性振动时效装置数学模型元件参数之间的关系;最后,以高刚度工件轧辊为例研究了其非线性超谐式振动时效方法和装置设计,提出了针对大刚度工件的振动时效方法和装置设计理论。

How to achieve the resonance and dynamic stress so as to reduce the residual stress of high stiffness workpieces remains a hot potato because during use the exciting frequency of traditional VSR devices is far lower than the lower order natural frequency of the high stiffness workpiece.A novel VSR device with nonlinear superharmonic vibration and its mathematical model are proposed in this paper.The mechanisms to reduce the residual stress of this device is studied from the points of exciting frequency and exciting force.Then the condition of the device system to happen the superharmonic vibration is obtained.The parametric relations of the system elements are gained from the relation of dynamic stress and the response amplitude of the superharmonic vibration.