基于归一化参数模型的涡轮盘和涡轮叶片蠕变分析

为完整描述构件3个阶段的蠕变变形计算，结合所发展的各向同性材料的归一化参数蠕变模型，进一步拓展到正交各向异性材料的归一化参数蠕变模型并进行适用性验证。应用所编制的子程序对高温材料涡轮盘和定向结晶材料涡轮叶片结构，进行了蠕变变形及应力松弛效应计算分析。结果表明：经过一定时间的蠕变变形，涡轮盘和涡轮叶片的高应力区会出现应力松弛。总体上轮盘的应力分布更加均匀，静力分析得到的轮盘中心孔、螺栓孔边和轮缘辐板过渡段处高应力区，由于存在蠕变变形，均出现较明显的应力松弛，但是盘中心孔处的应力松弛幅度较小，可能长时间处于高应力状态，应作为结构设计的危险部位重点考查；涡轮叶片也具有同样的应力松弛蠕变效应，特别是随着蠕变变形的增大，叶尖径向变形(位移)逐渐增大，在结构设计中，应考虑叶片叶尖与机匣长期工作径向碰摩而带来的不利影响。

Analysis of Creep Based on Normalized-Parameter Model for Turbine Disk and Blade

In order to completely describe the creep deformation calculation of three stages for components and combine normalizedparameter creep model of isotropic material, the normalized-parameter creep model of orthotropic material was developed further and the applicability verification was performed. The creep deformation and stress relaxation behaviors of a turbine disk of high temperature material and blade of directional crystallization material were performed by using subroutine program. The results show that stress relaxation is occurred at the high stress region of the turbine disk after a period of creep deformation, and the overall stress distribution is more uniform.In addition, the static analysis of the turbine disk shows that there are high stresses near the center hole, bolt hole and the transitional fillet of the turbine disk. There is stress relaxation obviously because of creep deformation. However, the amplitude of the stress relaxation at the center hole of the disk is relatively small which may maintain the stress at high level. Thus, the center hole of the disk as danger position should be checked emphatically in the structure design. The turbine blade has same creep effect of the stress relaxation, especially, the radial deformation displacement of tip increases with the enlargement of creep deformation. In the structure design, the adverse effects of the radial rubbing between blade and case in long term operation brought should be considered. Key words: turbine disk; turbine blade; creep deformation; stress relaxation; normalized-