学术论文

      基于非线性振动的上悬式离心机可靠性分析

      Reliability analysis of a top-suspended centrifuge based on nonlinear vibration

      摘要:
      为了研究非线性振动对上悬式离心机频率可靠性的影响,用有限元法建立包含电磁参数、机械结构参数和糖膏流体参数的上悬式离心机主轴系统非线性动力学方程.采用多尺度法求解系统非线性振动频率因子,结合人工神经网络技术,拟合出材料参数与固有频率之间的关系.以频率可靠性理论为基础,依据可靠性的关系准则,定义系统的失效模式,建立基于非线性振动的上悬式离心机主轴系统的可靠性模型,并进行了仿真分析,给出系统工作转速应该避开的不可靠运行区域.研究结果表明,当系统转速为 152 r/min、197 r/min、417 r/min 和 811 r/min时,系统的可靠度明显降低,并趋向于0,其中当转速为152 r/min、197 r/min、417 r/min时,是由于线性共振失效引起的;而当转速为811 r/min时,是由于非线性组合共振失效引起的.即考虑非线性因素时,系统产生了非线性频率因子,当该非线性频率因子与系统的固有频率相近时,系统的可靠度将趋向于零.因此,系统的正常工作转速不仅要避开线性共振引起的不可靠区域,也要避开非线性共振引起的不可靠区域.
      Abstract:
      The top-suspended centrifuge is studied and the effect of the nonlinear vibration on the reliability of the top-suspended centrifuge is analyzed.The nonlinear dynamic equation, which includes electromagnetic parameter, mechanical parameter and massecuite parameter, is built by using the finite element method.Multi scale method is used to solve the frequency factor of nonlinear vibration of the system, and the relationship between the material parameters and the natural frequency is fitted on the basis of artificial neural network technology.The frequency factor of the nonlinear vibration is gotten by multiple scales.Based on the reliability theory, the failure mode of the system is defined, and the nonlinear dynamic equation of the system is established by the finite element method, then an example is presented.The results show that when the rotation speed is close to 152 r/min、197 r/min、417 r/min and 811 r/min, the reliability of the system is close to zero, while the reliability failure at 152 r/min、197 r/min、417 r/min are owing to linear resonance failure, and the reliability failure at 811 r/min is owing to nonlinear combination resonance failure.With consideration of nonlinear vibration, the system contains nonlinear frequency factors, its nonlinear frequency factor is close to the natural frequency, and the reliability of the system is close to zero.So the working rotation speed should avoid not only the linear resonance unreliable area, but also the nonlinear resonance unreliable area.
      作者: 杨旭娟 [1] 张振 [2] 王汝贵 [2] 李宇龙 [2]
      作者单位: 广西大学机械工程学院, 广西南宁530004;广西制造系统与先进制造技术重点实验室, 广西南宁530004;广西高校临海机械装备设计制造及控制重点实验室培育基地, 广西钦州535000 广西大学机械工程学院,广西南宁,530004
      年,卷(期): 2017, 42(2)
      分类号: TH113 TK730.2
      在线出版日期: 2017年5月16日
      基金项目: 国家自然科学基金资助项目,广西高校科研基金项目资助,广西制造系统与先进制造技术重点实验室主任基金项目,广西高校临海机械装备设计制造及控制重点实验室培育基地开放课题基金资助