螺纹摩擦对螺栓轴向力-伸长量特征曲线的影响

基于超声波技术,通过对螺栓进行拉伸试验,研究了不同外载下螺栓轴向力-伸长量特征曲线的差异,分析了螺纹摩擦对螺栓轴向力-伸长量特征曲线的影响.结果表明:螺栓的单向拉伸与扭转拉伸因受到的载荷方向不同而导致其屈服点不同;螺栓前期拧紧标定过程中螺纹摩擦对螺栓轴向力有很大影响,会影响后续子系统螺栓夹紧力的大小;不同的螺纹摩擦状态...

Influence of Thread Friction on Bolt Axial Force-Elongation Characteristic Curve

Based on ultrasonic technology,through the tensile tests of bolts,the differences of bolt axial force-elongation characteristic curves under different external loads were studied,and the influences of different thread frictions on bolt axial force-elongation characteristic curves were analysed.The results show that the yield points of bolts under uniaxial tension and torsional tension are different due to different load directions.In the process of bolt pre tightening calibration,the thread friction has a great influence on the bolt axial force,which will affect the bolt clamping force of subsequent subsystem.Different thread friction states lead to different axial strain rates during tightening and different characteristic curves.The greater the thread friction coefficient is,the greater the torsional stress is and the lower the yield point is.If the axial tensile speeds are the same,the slopes of characteristic curves are the same,whether it is the normal thread friction between coatings or the use of oil to reduce friction.The friction between metals without coating will lead to the plastic deformation of thread tip,and the slope of the elastic section of the characteristic curve is quite different.