在高强度螺栓的摩擦连接中,连接副在紧固时需要保证一定允差下的预拉力。因为预拉力过小时,会使摩擦连接松动而不够紧固;而预拉力过大,当螺栓又承受外加载荷时,会造成过载而损坏。此外,减少紧固螺栓时的摩擦系数,可以降低紧固扭矩,也可减轻紧固时的劳动强度和减少工作量。这些就是本工艺试验的目的。在摩擦连接设计中,螺栓的设计预拉力是最主要的参数之一,而保证螺栓预拉力精度则是施工中的关键。螺栓副在紧固时,扭矩M和螺栓预拉力N的关系, In the high-strength bolt friction connection, the connection in the fastening need to ensure that the pre-tension under a certain tolerance. Because the pre-tension is too small, it will loose the friction connection is not tight enough; and pre-tension is too large, when the bolt and bear the applied load, it will cause overload and damage. In addition, reducing the coefficient of friction when tightening the bolts reduces the tightening torque, as well as reducing labor and labor required to tighten the bolts. These are the purpose of this process test. In the friction connection design, the design of the bolt pre-tension is one of the most important parameters, and to ensure the accuracy of pre-tension bolts is the construction of the key. When the bolt is tightened, the relationship between the torque M and the bolt pretension N,