机翼盒段连接结构疲劳性能影响因素及有限元分析

Study on Influencing Factors of Interconnected Structures Fatigue Performance of Wing Box and Its Finite Element Analysis

针对国产某型飞机机翼翼盒典型连接区结构,设计试验件进行疲劳试验,对比分析高锁螺栓不同装配工艺对其疲劳性能的影响。结果表明:对高锁螺栓施加一次拧紧工艺后,再施加适当的二次拧紧力矩,能够有效改善连接结构的疲劳性能。其次,建立连接结构的三维有限元模型,基于正交试验法分别研究螺栓拧紧力矩、板间摩擦系数和螺栓材料弹性模量对基板孔边应力集中系数的影响。研究发现,该3种因素均对孔边应力集中系数有较大影响,其中螺栓拧紧力矩的影响最为显著,表明了适宜的二次定力工艺是提高连接结构疲劳性能的一种有效手段。

Fatigue tests of the specimen designed according to the typical interconnected structures of a certain airplane’s wing box were carried out to analyze the effects of different assembly processes of high locked bolts on fatigue performance. The results show that the fatigue performance of interconnected structures can be improved effectively by exerting an appropriate second–tightening torque to high locked bolts after the current assembling processes. A three–dimensional finite element model was established to investigate the effects of tightening torque of bolts, friction coefficient between plates as well as elastic modules of bolts on the stress concentration factor of the hole edge in basic plates.The study indicates that all the three factors have great influence on the stress concentration factor of the hole edge.Furthermore, tightening torque of bolts has the most significant impact. It also shows that exerting a second–tightening torque is an effective mean to improve the fatigue performance of interconnected structures.