典型机身结构随机声疲劳寿命分析研究

The analysis on random acoustic fatigue life of the typical fuselage structure

以某型飞机机身盒段为研究对象,建立了其仿真分析模型。将模型导入ABAQUS软件中进行模态分析。结合声学基本理论和随机振动理论,在LMS Virtual.Lab软件中采用间接边界元法对结构进行声振耦合计算。采用Miner疲劳寿命估算法则以及Goodman直线校正方法对平均应力进行了修正,结合材料的S-N曲线求得结构的疲劳寿命。结果显示,损伤严重的区域依次为机身盒段上蒙皮和周边蒙皮,底部的损伤最小。研究了声压级和结构形式对机身盒段声疲劳寿命的影响,结果表明,以衰减后的声压级作为声载荷以及含罐体的双层结构都使得机身盒段的声疲劳寿命增加。

Taking a certain aircraft fuselage box segment as the research object,a simulation analysis model is established.The model is imported into the ABAQUS software,and the modal analysis is performed according to the constraints of the fuselage.Combined with the basic theory of acoustics and random vibration theory,the indirect boundary element method is used to calculate the acoustic-vibration coupling of the structure in LMS Virtual.Lab software.The Miner's rule is used as the fatigue life estimation rule,and the average stress is corrected by the Goodman linear formula.Combined with the S-N curve of the material,the fatigue life of the structure is finally obtained.The area with serious damage is the skin and the peripheral skin on the fuselage box segment,and the damage at the bottom is the smallest.Finally,the effects of sound pressure level structure type are studied from the many factors affecting the acoustic fatigue life of the structure.The analysis results show that the sound pressure level after attenuation used as the acoustic load and the structure type of the tank make the structural acoustic fatigue life increase,which provides a reference for the structural anti-acoustic fatigue design.