影响航空发动机结构寿命的载荷分散系数

国内外多个航空发动机设计通用规范和型号规范分析表明，关于航空发动机疲劳分散系数的规定和方法较为宽泛，缺乏严格的定义和分类，给工程应用带来一定的困扰。将航空发动机疲劳分散系数分为结构分散系数和载荷分散系数，并分别给出了定义。发动机结构的载荷分散系数计算方法被给出，并分别以某航空发动机主要载荷的起动次数和大状态工作时间为例，研究了载荷分散系数及其随工作时间的变化规律。基于数学仿真方法，研究了固定任务混频和变任务混频下的载荷分散系数随工作时间的变化规律。结果表明，该型发动机的载荷分散系数基本在1.0~2.0之间，且随着工作时间的累积呈现下降趋势，其下降速率与载荷性质有关。

Load scatter factors affecting aero engine structure life

Investigations into multiple domestic and foreign design general specifications and model specifications for aero engines reveal that the regulations and methods for fatigue scatter factors of aero engines are relatively broad without strict definitions and classifications. According to the influences on the engine fatigue life, the fatigue scatter factors for aero engines are categorized into structural scatter factors and load scatter factors, and their definitions are respectively given. We then propose a calculation method for the load scatter factor. Based on the number of start-ups of the main loads and the running time of large states for an aero-engine, the load scatter factor and its variations with the running time are studied. The variation laws of the load scatter factor with the running time under the fixed tasks frequency mixing and the variable tasks frequency mixing are explored using mathematical simulation. Results show that the load scatter factor for the aero-engine is between 1.0 and 2.0, exhibiting a downward trend with the increase of the running time, and its decline rate is related to the nature of the load.