应变能理论在端面齿连接段刚度的应用方法研究

端面齿应用在重型燃气轮机拉杆转子轮盘连接中是重要的传扭部件.对于特殊齿形结构的端面齿连接段刚度,很难通过传统工程方法得到.针对真实某型燃气轮机轮盘端面齿结构,提出端面齿连接段模化方法.基于有限元软件ANSYS,采用ANSYS ICEM建立三维周期对称有限元接触模型和整体模型,运用有限元方法和应变能理论,提出拉伸刚度修正系数和扭转刚度修正系数以表征端面齿不连续连接段刚度.考虑实际机组的运行工况,采用三维有限元计算在不同预紧力和扭矩下的应变能,得到拉伸刚度修正系数和扭转刚度修正系数.所得结论可为燃气轮机拉杆转子模化提供理论依据和方法.

Study on the Stiffness Calculation of Hirth Facial Serration Couplings Using Strain Energy Theory

As an important element of transferring torsional moment,Hirth facial serration couplings have great significance in the bolted rotor of heavy-duty gas turbine.It is difficult to obtain the stiffness of the special structure of Hirth facial serration couplings in gas turbine rotor by a conventional way.A modelling method of Hirth facial serration couplings is proposed based on an actual gas turbine.Three dimensional symmetric contact shaft model and integral model containing three pairs of Hirth facial serration couplings were built based on finite element software ANSYS and meshing software ANSYS ICEM.Using finite element method and strain energy method,tensile stiffness coefficient and torsional stiffness coefficient were put forward to analyze the discontinuity of the structure with Hirth facial serration couplings.The 3-D finite element analysis was used to calculate the strain energy of the model with different pre-tighting forces and torsional moments,taking the real working condition into account.The tensile stiffness coefficient and torsional stiffness coefficient were obtained,which provides a theoretical basis for the gas turbine rotor modelling.