锯齿冠叶片瞬态热应力模拟试验

锯齿冠涡轮叶片在发动机起动过程中会产生较大的热应力。这种热应力与离心应力、气动应力合成的综合应力可能引起涡轮叶片的低循环疲劳失效。建立了瞬态温度场的热传导、热弹性相似关系 ,通过满足热相似条件的热模拟试验 ,分析了某型锯齿冠涡轮叶片在发动机起动过程的瞬态热应变和热应力 ,其结果为分析该型叶片的低循环疲劳失效原因提供了依据 ,同时讨论了叶冠结构因素对热应力的影响。

The Modelling Experiment of Transient Thermal Stresses for the Turbine Blade with "Z" Shroud

The turbine blade with "Z" shroud can produce high thermel stress due to structure deformation compatibility during engine start. The synthesis of thermal, centrifugal and aerodynamic stresses may cause the low cycle fatigue failure of the blades. The similarity relation of thermal conduction and thermoelasticity is established in the transient temperature field. The transient thermal strains and stresses of the blades are obtained by means of the modelling experiment. The results have been provided as the basis of the failure analysis of the turbine blade with "Z" shroud, and the influnce of shroud structure factor to the thermal stress is discussed.