螺栓扭矩系数影响因素的试验研究

在螺栓连接结构中,为保证连接的可靠性,必须为螺栓提供合适的预紧力。工程中通常采用扭矩法装配螺栓连接结构,因此需要确定预紧力与扭矩之间的关系(即扭矩系数),以施加合适的装配扭矩。本文对输电塔中常用的M16镀锌螺栓进行预紧力试验研究,测试分析了螺栓强度等级、有无垫圈和有无润滑对螺栓连接副扭矩系数的影响。研究结果表明,高强度螺栓比普通螺栓的扭矩系数小,数据离散性也小;无垫圈的螺栓比有垫圈的螺栓扭矩系数小,但数据离散性大;有润滑的螺栓比无润滑的螺栓扭矩系数小,数据离散性也小。本文同时探讨了如何控制、调整扭矩系数,以及螺栓连接中要注意的问题,为设计和施工单位提供参考。

Experimental Study of the Factors Effecting on Bolt Torque Coefficient

In order to ensure the reliability of bolt joint in bolted structures, suitable pretightening force is essential. Torque method is commonly used in engineering. So it is necessary to determine the relation between the pretightening force and the torque (torque coefficient) before applying appropriate assembly torque. In this paper, an experimental study of pretightening force for M16 galvanized bolts commonly used in transmission tower was carried out, and the effect of bolt strength grade, the presence or absence of washer and the presence or absence of lubrication on the torque coefficient of bolt joint was measured respectively and analyzed. Results show that the torque coefficient and its data discreteness of high strength bolt are smaller than that of ordinary bolt; the torque coefficient of bolt without washer is smaller than that of bolt with washer, however its data discreteness is larger; the torque coefficient and its data discreteness of bolt with lubrication are smaller than that of bolt without lubrication. Furthermore, the torque coefficient control, adjustment and some key problems about bolt connection are also discussed in this paper, which can provide a reference for engineering applications.