螺栓连接接口轴向振动能量耗散特性研究

Study on Energy Dissipation of Axial Vibration in Bolted Joint

根据螺栓连接接触面的轴向接触微观特征,将接触面的接触方式分为峰-峰接触和峰-谷切向接触,提出了螺栓连接轴向振动的动力学模型。在假定接触面出现简谐运动条件下,推导出接口阻尼力的解析表达式和接口能量耗散的关系式。该式表明,轴向振动单位周期内的能耗包括粘性阻尼和干摩擦阻尼能耗两部分,这两部分能耗都与振动幅值和固有频率的平方成正比。粘性阻尼能耗与频率比和阻尼比成正比,干摩擦阻尼能耗与接触面峰-谷切向接触压力与总压力之比成正比,而与振动幅度和压缩位移比成反比,与接口的拉压刚度比成非线性关系。

Based on the microscopic characteristics of contacting surface in bolted joint,the contacting types are classified as two tapes,that is,the peak-peak contacting and tangent peak-valley contacting. A dynamic model of axial vibration in bolted joint is presented.On the assumption that there is a resonance movement on the contacting surface,the damping force and dissipating energy in bolted joint are formulized.The formulas indicate that during a cycle of movement,the dissipated energy includes the viscosity damping and coulomb damping dissipations,which are both proportional to the square of magnitude and the nature frequency.The viscosity dissipated energy is also proportional to the ratio of exciting frequency/natural frequency and damping ratio,and that the coulomb dissipated energy is proportional to the ration of tangent peak-valley contacting force/total contacting force in bolted joint,and inversely proportional to the ratio of moving magnitude/preloaded pressed displacement and has a non-linear relationship with the ratio of extension / press stiffness of bolted joint.