考虑惯性力的螺栓临界松动载荷影响因素分析与试验

Analysis and test on influencing factors of the critical loosening load of bolts considering inertia force

为准确探究横向振动工况下螺栓连接的松动特性,综合考虑了局部滑移与扭矩滑移的影响,建立了考虑惯性力的螺栓连接模型,对螺纹周向不同位置进行受力分析,得到了计算螺栓临界松动载荷的理论计算方法,并利用横向振动试验进行了验证,结果表明该理论计算方法具有更高的准确性。定量计算了不同预紧力、螺纹面摩擦因数、振动次数、螺距、振动频率、螺纹升角等参数下的螺栓临界松动载荷,揭示了螺栓松动的主要影响因素。当增大预紧力、螺纹面摩擦因数,降低振动次数、螺距、振动频率和螺纹升角时,螺栓临界松动载荷随之增大,有利于提高螺栓连接抵抗自松弛的防松能力。研究结果对螺栓连接防松设计具有指导意义。

In order to accurately explore the loosening characteristics of bolt connections under transverse vibration conditions,the influences of local slip and torque slip were comprehensively considered,a bolt connection model considering inertial force was established,the forces at different positions of the screw threads were analysed,and a theoretical calculation method was proposed for calculating the critical loosening load of bolts,which was then verified by the transverse vibration test.The results show that the theoretical calculation method has higher accuracy.The critical loosening load of bolts under different condition parameters such as the preload,friction coefficient of thread surface,vibration times,pitch,vibration frequency and thread rise angle was quantitatively calculated,and the main influencing factors of bolt loosening were revealed.When the preload and friction coefficient of thread surface are increased and the vibration times,pitch,vibration frequency and thread rise angle are reduced,the critical loosening load of bolts will increase,which is conducive to improve the anti-loosening ability of bolt connection against selfloosening.The research results have a guiding significance for the design of bolt-joint locking.