螺栓连接鼓筒转子结构动力学特性分析

Analysis of dynamic characteristics of a bolted drum rotor structure

以螺栓连接鼓筒转子为研究对象,基于有限元软件,首先建立了减缩梁-壳-弹簧混合单元模型;其次通过仿真与实验的固有特性对比验证了减缩模型的准确性;最后分析了螺栓个数、螺栓松动、系统转速对螺栓连接鼓筒转子结构结合面的时变刚度和系统的响应特性的影响规律。研究结果表明:螺栓个数、螺栓松动与系统转速对连接结构的时变刚度和响应特性均有一定的影响,随着螺栓个数的增多,结合面连接刚度不断增大,系统的非线性特性不断减弱;螺栓松动导致连接刚度发生较大波动,并且随着松动个数的增多,系统非线性不断增强;随着系统转速的增大,螺栓连接时变刚度增大,但转速越高其刚度波动越大,导致系统非线性增强。

In this paper,a reduced beam-shell-spring mixed element model is established,and the natural characteristic of the system is analyzed based on the model.The accuracy of the model is verified by comparing the results with the experimental test results.Finally,the influence of the bolt number,the bolt looseness and the system speed on the time-varying stiffness and response characteristics of the bolted drum rotor structure are discussed.The results show that the number of bolt,the loosening of the bolt and the speed of the system have certain influences on the time varying stiffness and response characteristics of rotor system with bolt joints.With the increase of the number of bolts,the stiffness of the bolt connection will increase and the nonlinear characteristics of the system will be weak.The loosening of the bolt leads to the larger fluctuation of the connection stiffness,and as the number of loosened bolt increases,the nonlinearity of the system will increase.The stiffness of the bolt connection increases with the increase of the speed of the system,but the higher the speed is,the greater the fluctuation of the stiffness of the system will be,which will lead to the enhancement of nonlinear characteristics of the system.