【摘要】 周向拉杆转子结构在燃气轮机中非常常见，而转子结构中普遍存在的拉杆及接触层对转子-轴承-密封系统的动力学特性具有非常重要的影响。在本研究中，建立了周向分布拉杆的力学模型和表征轮盘之间接触效应的非线性接触刚度矩阵，该接触刚度矩阵由七个刚度系数组成，这七个刚度系数可以综合表征接触层横向刚度，剪切刚度，弯曲刚度，扭转刚度，并且该矩阵能够考虑转子变形对于刚度系数的影响。结合基于短轴承理论并且经过试验验证的非线性油膜力模型和Muszynska密封力模型建立了周向拉杆转子-轴承-密封系统的动力学模型。采用了Newmark-β法对动力学方程进行了求解，并采用三维频谱图分析了预紧力大小和预紧力不均对周向拉杆转子-轴承-密封系统的非线性动力学特性的影响规律。结果表明，接触刚度以及故障拉杆的相对位置对拉杆转子-轴承-密封系统的稳定性及频率成分影响明显。更多还原

【Abstract】 The circumferential rod-fastening rotor structure is very common in gas turbines,and the tie rods and contact layers commonly present in the rotor structure have a very important impact on the dynamic characteristics of the rotor-bearing-seal system. In this study,a mechanical model of the circumferentially distributed tie rods and a nonlinear contact stiffness matrix that characterizes the contact effect between the wheels are established firstly. The contact stiffness matrix is composed of seven stiffness coefficients,which can comprehensively characterize the lateral stiffness,shear stiffness,bending stiffness,and torsional stiffness of the contact layer,and the influence of rotor deformation on stiffness coefficients the matrix is considered in the matrix. Then,a dynamic model of the circumferential rod-fastening rotor-bearing-seal system is established by introducing the nonlinear oil film force model based on the short bearing theory and verified by experiments and the Muszynska sealing force model. The Newmark-β method is used to solve the dynamic equations,and the three-dimensional spectrogram is used to analyze the influence of the magnitude and uneven distribution of the pre-tightening force on the nonlinear dynamic characteristics of the circumferential rod-fastening rotor-bearing-seal system. The results show that the contact stiffness and the relative phase of failed tie rods have significant effects on the stability of the rod-fastening rotor-bearing-seal system.更多还原