机身蒙皮划窝对结构细节疲劳额定值的影响  

Influence of Countersink of Fuselage Skin on Detail Fatigue Rating of Structure

作　　者：彭乾坤 周颜 张彦军 曾建江[1] 孙琰翔 PENG Qiankun;ZHOU Yan;ZHANG Yanjun;ZENG Jianjiang;SUN Yanxiang(College of Aerospace Engineering,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China;AVIC The First Aircraft Institute,Xi'an 710072,China)

机构地区：[1]南京航空航天大学航空学院,江苏南京210016 [2]航空工业第一飞机设计研究院,陕西西安710072

出　　处：《机械制造与自动化》2023年第6期36-39,共4页Machine Building & Automation

摘　　要：飞机机身蒙皮疲劳破坏是需要重点关注的问题,为评测连接方式(沉头与平头)对其疲劳性能的影响,选取典型双剪搭接结构进行试验研究。通过试验测定结构疲劳寿命,计算得到结构细节疲劳额定值(DFR)。可以得知,沉头结构DFR值降低了约22%。利用理论方法计算结构DFR值,对比试验数据,两种方法平均误差为2.10%,验证理论方法的可靠性,为机身蒙皮结构疲劳性能的研究提供参考。计算不同蒙皮厚度下结构DFR值,得知平头结构随蒙皮厚度增加DFR值逐渐下降;对于沉头结构,蒙皮厚度太大或太小均会降低结构DFR值,选择1.5 mm、1.8 mm厚度蒙皮较合适。The fatigue failure of aircraft fuselage skin is a focus needing to be attended to.To evaluate the influence of connection mode(countersunk head and flat head)on its fatigue performance,typical double-shear lap structures were selected for experimental study.The fatigue life of the structure was determined by test to abtain the DFR value of the structure.It is found that the countersunk head reduces the DFR value of the structure by about 22%.The comparison between the DFR value of the structure calculated by theoretical method and the test data shows that the average error of the two methods is 2.10%,which verifies the reliability of the theoretical method and provides a reference for the study of the fatigue performance of the fuselage skin structure.The DFR value of the structure with different skin thickness was calculated finding that the DFR value of the flat head structure decreases gradually with the increase of skin thickness.For the structure with countersunk head,excessive large or small skin thickness will reduce the DFR value of the structure,and 1.5 mm and 1.8 mm skin thickness will be better choices.

关 键 词：疲劳 双剪搭接 肖维勒准则 细节疲劳额定值 疲劳寿命 

分 类 号：V215.5[航空宇航科学与技术—航空宇航推进理论与工程]