螺纹结构力矩及其衰退机理分析

摘要

阐述了得出螺栓拧紧力矩的方法，结合预紧力和预紧力矩之间的关系，给出其理论方程和实验方程，分析了预紧力、螺纹摩擦转矩和螺母支承面摩擦转矩三者的分配情况。以此为基础，从结构变形与应力释放、材料表面摩擦力变化等方面对力矩衰退的原因进行了初步分析，并提出设定拧紧力矩安全系数和定期校核拧紧的措施，供螺纹结构设计及其使用维护参考。%The method to get screw torque is described. Combined with the relationship of threaded preload and torque, the theoretical formula and test formula are provided to describe the division of the pre-tightening, the friction torque of screw and the friction torque of nut’s surface. Based of those, the torque degeneration theory is analyzed from the aspects of structure distortion, stress release, friction alteration and so on. Then the response measures are advanced such as setting torque safe factor and periodic tighten. All those are for the reference of screw structure design and use.