【作者】 徐飞；

【导师】 彭震中； 王璋奇；

【作者基本信息】 华北电力大学（河北） ， 机械设计及理论， 2004， 硕士

【摘要】 影响汽轮机叶片强度的参数(如材料特性、叶片转速、载荷等)都具有一定程度的不确定性,从而叶片的变形、应力等响应也具有不确定性。本文基于二阶摄动技术研究叶片强度分析的随机有限元方法。建立了汽轮机末级长扭叶片的随机有限元计算模型——旋转变截面扭梁模型,推导了考虑转速影响时在轴向变形、弯曲变形和剪切变形共同作用下模型的单元刚度矩阵和载荷列阵。基于局部平均法离散随机场以获得随机参数的统计特性,将其应用于叶片强度计算的摄动随机有限元方程中,并编制了二阶摄动随机有限元分析软件。利用该软件分别计算了转速、弹性模量和蒸汽作用力等为随机变量时叶片强度的统计特性。通过与Monte Carlo数值模拟方法所得结果对比,验证了本文方法的正确性。更多还原

【Abstract】 The parameters that affect the strength of the turbine blade in the steam turbine are usually uncertain, such as the material characteristic, the rotating speed and the load, and so on. So the distortion and stress are also uncertain. Based on the second-order perturbation technique, the stochastic finite element method(SFEM) of the strength analysis of the turbine blade is introduced in this paper.A SFEM model named rotating twisted and tapered beam that is used in the longest turbine blade in the steam turbine is established. Including the rotation effects, due to the deformation of axial direction, bending and shearing, the element matrix and load matrix are educed. With the help of local average method to discrete the random field, the statistical characteristic of random parameter is attained, and it is used to the perturbation stochastic finite element method(PSFEM) equation that is good at calculating the strength of turbine blade. Finally, the software of second-times PSFEM is formed. When the rotating speed, the elasticity modulus and steam load were considered as random parameter, the statistical characteristic of strength of turbine blade can be calculated by this software, and Monte Carlo simulation method is used to check up the validity. Xu Fei (Mechanic Design and Theory) Directed by prof. Peng Zhenzhong & prof. Wang Zhangqi更多还原