基于DFR的战斗机疲劳关键部位日历寿命设计方法

Calendar life design method for critical fatigue parts of fighter based on DFR method

战斗机疲劳关键部位日历寿命难题的核心在于缺少具有普适性的日历寿命设计方法。为此,首先基于战斗机飞行载荷特征,分情况讨论了地面停放、低空飞行、高空飞行时环境对战斗机结构疲劳性能的影响。其次基于腐蚀条件下战斗机结构耐久性设计DFR法及疲劳损伤累积理论,建立了战斗机结构日历寿命分析模型,并从服役环境、飞机类型、材料及结构的角度分析了日历寿命影响因素。然后基于此模型建立了战斗机疲劳关键部位日历寿命设计方法,并且通过与传统日历寿命评定技术的对比及某型战斗机外翼2墙日历寿命设计示例,阐明此法的可行性、适用性及优越性。

The key problem of calendar life in critical fatigue fighter parts lies in the lack of universal calendar life de⁃sign methods.To solve this problem,we first discuss the influence of the environment during ground parking,low alti⁃tude flight,and high altitude flight on the structural fatigue performance of fighters,based on the characteristics of fighter flight load.Secondly,a calendar life analysis model for the fighter structure is established based on the DFR method for durability design of fighter structures under corrosive conditions and the fatigue damage accumulation theory,and the influencing factors of the calendar life are analyzed from the perspective of service environment,air⁃craft type,material and structure.Thirdly,the calendar life design method for critical fatigue fighter parts is established based on this model.Finally,the feasibility,universality and superiority of this method are illustrated by comparing with the traditional calendar life evaluation technology and an example of the calendar life design of the 2nd wall on the outer wing of a certain fighter.