单面螺纹抽钉干涉配合复合材料连接结构的疲劳性能研究

通过疲劳试验研究了单面螺纹抽钉干涉配合复合材料连接结构的疲劳性能,分别考虑了紧固件类型、干涉配合量、搭接板材料及铺层次序等影响因素。采用了拉压疲劳试验,拉压比R=-1,循环应力水平则根据静载极限挤压强度值选定。根据疲劳试验循环应力和疲劳寿命曲线(S-N曲线),得到了不同影响因素对疲劳寿命的影响规律。结果表明,选择适当的干涉配合量、紧固件类型及搭接板均能提高结构的疲劳寿命,4种不同主板铺层次序均对结构疲劳寿命影响不大。

Effect of Several Influencing Factors on Fatigue Behaviour of Interference-Fit Bolted Composite Joints

An experimental investigation was conducted to determine the effect of several influencing factors on the fatigue behavior of interference-fit bolted composite joints. The types of bolts, the sizes of interference fit, different materials of laps, and stacking sequences of main laminates were separately considered. Tension-compression reversed force/stress ratio, R=-1, was selected to evaluate the fatigue tests. The appropriate levels of fatigue stress were determined by the ultimate bear-ing strength of the fastener structure obtained from the static tensile tests. The bearing stress and the fatigue life (S-N) data of all specimens were presented and the relationship between influencing factors and fatigue life were obtained. The experimental results show that the appropriate size of interference fit, the right type of fasteners, and the matched laps could improve the fatigue life of composite joints; however four stacking sequences of main laminates are not sensitive to the fatigue life of com-posite joints.