带密布气膜冷却孔的涡轮叶片等效应力分析方法研究

以带气膜冷却孔的航空燃气涡轮发动机涡轮叶片为研究背景,引入了等效概念对密布小孔结构进行了详细的应力-应变分析。这种等效分析方法是把多孔材料转化为具有等效材料常数的等效实体材料。根据MARC大型通用软件的线弹性及弹-塑性有限元应力分析结果,将小孔效应转化为等效弹性常数及等效应力-应变曲线。最后以某发动机高压涡轮工作叶片为例,将得到的等效材料参数引入到叶片的有限元强度计算中,从而得到考虑密布孔影响的涡轮叶片应力应变场,并通过子模型计算得到更为准确的孔边最大应力。

Investigation into Equivalent Stress Analysis Method for Turbine Blades with Densely Distributed Film Cooling Holes

An equivalent no-perforated plate concept is introduced in the stress-strain analysis for densely-distributed film cooling holes on turbine blades of gas turbine engines.The equivalent analysis method is based on treating the perforated material as an equivalent solid material with modified material constants.According to the results of linear elastic and nonlinear elastic-plastic analysis by the MARC code,the effect of film cooling holes is substituted by equivalent material constants and equivalent stress-strain curves.As an example,the equivalent material constants are introduced into a FEM component strength analysis for the high-pressure turbine blades of an air engine to obtain the influence of film cooling holes on the stress and strain distribution.More accurate hole stress can be obtained by the further global-local model calculation.