粉末冶金涡轮盘寿命稳健性分析与设计

Life-Time Analysis and Design of Powder Metallurgy Turbine Disk

摘要:

基于限界不确定性原理和方法，对粉末冶金涡轮盘寿命进行稳健性分析与设计。首先，系统给出了分析方法：结合区间有限元方法，给出了在给定参数限界不确定性时，FGH95材料粉末冶金盘寿命的限界(上下限)。其次，分析了在满足粉末冶金盘设计寿命(以4000周次为例)时，各随机变量所要求的限界(偏差)范围和组合取值范围。此方法克服了经典可靠性理论对随机变量分布要求的严格性，适于工程应用，为盘的质量控制提供明确的指导和依据。

Abstract:

Based on boundary uncertainty theory, the service life of a powder metallurgy processed (PM) turbine disk has been analyzed. First, the general formulations are presented. The effects of the boundary uncertainty variables on PM disk life response are formulated mathematically by Taylor expansion based on the boundary uncertainty descriptions. In order to present the lifetime results (output), to a specified uncertainty a critical relative maximum deviation has been presented for the required bounds of the (input) variables. Using experimental data for the PW alloy FGH95, the boundary life of a FGH95 turbine disk has been derived. The two key bounded variables among all possible ones are chosen as an example, and the accepted jointed bounds for the two variables have been calculated to satisfy a specified fatigue life of more than 4 000 cycle number. The example shows the advantage of the boundary uncertainty than the classic probability method, and can be applied to a simple sample.