带鳍状凸肩结构汽轮机叶片的接触分析

为了研究大型汽轮机叶片旋转过程中鳍状凸肩间的接触状态,利用拉格朗日增广算法,采用三维有限元模型,计算了考虑摩擦情况下的凸肩间接触压力的变化情况,得出了接触压力与转速之间的关系,并计算了3000r/min下整圈叶片的固有频率.计算表明:当叶片转速达到400r/min时,鳍状凸肩开始接触,此后随着转速的增加,鳍状凸肩间的接触压力逐渐增大,接触面积不断扩大;当转速为1825r/min时,接触压力增加程度明显趋缓;转速为3000r/min时接触压力最大(700MPa),鳍状凸肩间的实际接触面积为设计接触面积的1/4左右.

Contact Analysis of Steam Turbine Blades With Fin Heaves

For rotating blades with fin heaves used in steam turbines, large deflection and contact effects must be taken into account. By using 3-D finite element model and the augmented Lagrangian formulation, contact pressure between fin heaves is analyzed. Contact friction considered, the relation curve of the contact pressure vs. rotating speed is obtained and intrinsic frequencies of blades at 3 000 r/min are calculated. Calculating resuits show that two neighbored fin heaves become to contact at rotating speed of 400 r/min. After this, contact pressure increases steadily as the rotating speed increases. However, as the speed reaches 1 825 r/min, increasing of the contact pressure becomes to slow down apparently. At 3 000 r/min, the contact pressure reaches its maximum of 700 MPa and the contact area is about 1/4 of the design contact area.