机械设计教学中预紧螺栓连接问题的探讨

Discussion about the preloaded bolt connection in mechanical design course teaching

受轴向工作载荷的预紧螺栓连接是螺纹连接教学中的重要内容之一。由于实际预紧螺栓连接结构的复杂性,有时难于判别螺栓连接结构中的螺栓与被连接件,也就无从得到正确的螺栓刚度和被连接件刚度。对预紧螺栓连接中螺栓和被连接件的受力与变形特征进行了分析,当螺栓承受工作载荷时,螺栓底面相对于被连接件继续沿工作载荷方向变形,而被连接件的压缩变形得到一定程度的释放。依据这些基本特征可对预紧螺栓连接结构中的螺栓和被连接件进行识别,这对准确理解与合理设计预紧螺栓连接结构具有十分重要的意义,也期望对预紧螺栓连接的教学有所帮助。

Preloaded bolt connection with axial working load is one of the important contents in the thread connection teaching. Sometimes it is difficult to determine the bolt and the connected element and hence hard to obtain the correct stiffness of the bolt and the connected element due to the complexity of actual preloaded bolt connection structure. Characteristics of force and deformation of bolt and connected element in the preloaded bolt connection are analyzed,which shows that when the bolt bears the working load,the bolt continues to deform along the working load direction relative to the connected element,while some of the compression deformation of the connected element is released. Based on these characteristics,the bolt and the connected element in the preloaded bolt connection structure can be identified,which is useful for the accurate understanding and reasonable design of preloaded bolt connection structure and also helpful to the teaching of preloaded bolt connection.