中文摘要：

提出用围带或凸肩接触面上的法向作用力来表征叶片相邻围带或凸肩的接触关系，并通过迭代计算接触法向力从0转变为正的临界转速值（即接触转速）．迭代计算中，接触面上的法向作用力由三维接触有限元分析获得，并取上一次有限元分析结果作为本次有限元分析的初始值来提高收敛速度．应用该方法对工作转速为3000r／min的某200MW汽轮机组末级叶片相邻围带、凸肩的接触转速进行了计算．结果表明：迭代7次后接触转速的计算误差小于11．7r／min；该叶片围带、凸肩接触法向力随转速的加快而增大，且在工作转速下达到最大值．

英文摘要：

To determin the contact speed of neighboring shrouds or lacings for long blades of steam turbines, a method is proposed to use the normal contact force to characterize the relations of relevant contact surfaces, based on which the critical speed （i. e. contact speed） is calculated when the normal force changes from zero to positive. The normal contact force is obtained by 3D contact finite element analysis. To achieve better convergence of the analysis, previous analysis results are taken as initial values of the next analysis. The method has been applied to calculate the contact speeds of related shroud and lacing of a last stage blade in a 200 MW unit working at 3 000 r/min. Results show that the error of contact speed can be reduced to be less than 11.7 r/min after 7 times iterations; the normal contact force of both the shroud and lacing increases with rising rotational speed, which will reach the highest at working speed.