基于应力应变场强法的轮盘疲劳可靠性分析方法

Fatigue Reliability Analysis of Disk Based on Stress-Strain Field Intensity Method

关键词:  应力应变场强法  轮盘疲劳寿命  分布式协同响应面  可靠性分析

Key words:  Stress-strain field intensity method  Fatigue life of disk  Distributed collaborative response surface  Reliability analysis

摘要:

为了更精确地进行航空发动机轮盘的疲劳可靠性分析，考虑缺口区域应力应变分布对疲劳寿命的影响，通过有限元模拟试验确定材料场径，采用应力应变场强法对轮盘进行确定性疲劳寿命分析。考虑场强因子及各参数的随机性，利用分布式协同响应面建立疲劳可靠性分析模型，并建立基于应力应变场强法的轮盘疲劳可靠性分析流程。结果显示:99.90%可靠度下的轮盘疲劳寿命为9595循环，相比确定性安全寿命6557循环，轮盘具有一定的寿命裕度。而应力应变场强法与传统方法理论分析结果相比，传统方法分析结果偏小，趋于保守。验证了基于应力应变场强法进行结构疲劳可靠性分析的合理性。

Abstract:

In order to analyze the fatigue reliability of aeroengine disk more accurately， the influence of stress and strain distribution of notch vicinity on the fatigue life is considered. The material field radius is determined by finite element simulation and the deterministic fatigue life of disk is analyzed by stress-strain field intensity method. Considering the randomness of the field intensity and other parameters， the fatigue reliability model is established by using the distributed collaborative response surface， and the fatigue reliability analysis process of disk is subsequently proposed based on stress-strain field intensity method. The results show that the fatigue life of disk is 9595 cycles when the reliability is 99.90% and the disk has life margin compared with deterministic safe life which is 6557 cycles. By comparing the stress-strain field method with the traditional local stress-strain method， the theoretical analysis result of the traditional method is small and tends to be conservative. The rationality of structural fatigue reliability analysis based on stress-strain field method is verified.