螺栓拧紧过程中工况对复合材料连接结构夹紧力的影响

Effect of operating conditions on the clamping force of composite material structure during bolt tightening process

针对复合材料结构螺栓连接,拧紧工况的不同会改变端面和螺纹间的摩擦系数,从而影响到扭矩系数,使夹紧力随拧紧力矩变化的趋势十分复杂。首先对螺栓连接过程进行理论分析,得到了夹紧力和复合应力状态下螺栓屈服夹紧力的表达式。然后以某型号螺栓为对象进行试验研究,在规定的目标预紧力下,分别测得了不同润滑条件、垫圈条件和拧紧速度下的拧紧曲线。试验结果表明,在螺栓整个拧紧过程中,不同的润滑条件、垫圈条件和拧紧速度对夹紧力和拧紧力矩曲线的离散度、达到相同大小夹紧力时需要的拧紧力矩、夹紧力随拧紧力矩的变化趋势都有一定程度的影响。通过上述工况下螺栓拧紧中的夹紧力研究,可为复合材料构件螺栓连接结构及拧紧工艺设计的精准化提供一定参考和依据。

For composite material structure bolt connection, different operating conditions will change the friction coefficient between the bearing surface and the thread, thus affecting the torque coefficient, which makes the changing trend of the clamping force with tightening torque very complicated. Firstly, the theoretical analysis of the bolt tightening process was made and the express formulas of the clamping force and the bolt yield clamping force under the state of combined stress were obtained. Then, taking a certain type of bolt as the object for experimental research, under the specified target clamping force, the tightening curves under different operating conditions of lubrication, washer, and tightening speed were tested respectively. The test results show that, different lubrication conditions, washer conditions and tightening speeds have certain influences on the dispersion of clamping force and tightening torque curves, the tightening torque required when the clamping force reaches the same size, and the changing trend of clamping force with tightening torque. By studying the clamping force during bolt tightening process under the above operating conditions, it can provide some reference and basis for the precision of bolt connection structure and process design in composite material components.