阻尼结构对长扭叶片应力及振动频率的影响分析  

Study on the Influence of Damping Structure on Stress and Eigenfrequencyof Long Twisted Blade

作　　者：郑飞逸 张军辉 林兵 陈华梅 徐阳 何炜楠 牛春燕 ZHENG Fei-yi;ZHANG Jun-hui;LIN Bing;CHEN Hua-mei;XU Yang;HE Wei-nan;NIU Chun-yan(Hangzhou Steam Turbine Power Group Co.,Ltd.,Hangzhou 310022,China)

机构地区：[1]杭州汽轮动力集团股份有限公司,杭州310022

出　　处：《汽轮机技术》2024年第5期349-352,共4页Turbine Technology

基　　金：2021年杭州市高层次人才特殊支持计划项目;杭州汽轮动力集团股份有限公司资助项目(C新23-01、C研23-02)。

摘　　要：针对不同阻尼结构对长扭叶片应力及振动频率影响的问题,对仅具有围带阻尼的模型1和具有围带、中间阻尼的模型2展开分析。首先,利用ANSYS软件进行叶片结构分析,得到不同转速下叶片的应力和阻尼结构接触面的正压力;然后通过Greenwood-Williamson接触模型将正压力转化为接触刚度,使用Matrix27单元模拟接触刚度,进行叶片模态分析。研究表明,叶片最大应力出现在叶型顶截面与围带交接处,模型1与模型2的最大应力比为1.34:1;模型1接触面的接触刚度比模型2小,其同阶次同节径振动频率比模型2低;通过坎贝尔图分析发现,模型1有3个共振转速,其中2阶7节径共振转速的避开率不满足要求;模型2有2个共振转速,避开率均满足要求。研究表明,与模型1相比,模型2的应力与振动频率更能满足设计要求。In order to study the influence of different damping structure on stress and eigenfrequency of long twisted blade,two models of long twisted blade,Model 1 with shroud only and Model 2 with shroud and snubber,were presented and analyzed in this paper.Firstly,the static stress analysis ofblade was conducted by ANSYS,stress of blade was obtained,and normal contact force of neighboring shroud and snubber contact surface of adjacent blade under different rotational speeds were also obtained.Then,the Greenwood Williamson contact model was used to convert normal contact force into contact stiffness.Contact stiffness was simulated by Matrix27 element in the finite analysis model,and blade's modal analysis was conducted by ANSYS.The results show that maximum stress onblade occurs at the intersection of the blade top section and the shroud,the ratio of maximum stress between Model 1 and Model 2 is 1.34:1.Contact stiffness of Model 1's contact surface is smaller than that of Model 2's.Under the same order and same nodal diameter,model1's eigenfrequency is lower than that of Model 2's.According to Campbell diagram,Model 1 has three resonance speeds,and the avoidance rate of resonance speed of the 2nd order nodal diameter 7 does not meet the requirements.Model 2 has two resonance speeds,and both avoidance rates meet the requirements.The results indicate that Model 2's stress and eigenfrequency meet the design requirements better than Model 1's.

关 键 词：长扭叶片 阻尼结构 接触刚度 应力分析 振动频率 

分 类 号：TK263.3[动力工程及工程热物理—动力机械及工程]