基于应变的螺栓轴向紧固力测量及衰减规律的研究

Research on Axial Tightened-force Measurement of Bolts and Attenuation based on Strain

为了对地铁客车室门机构螺栓联接进行测量,以获得螺栓拧紧过程中轴向紧固力的大小以及拧紧之后轴向紧固力的衰减变化规律,采用了一种专用螺栓应变片法,通过螺栓拉伸试验机和高精度应变测量仪进行标定,拟合得到螺栓轴向紧固力与应变的关系式,并应用于实际装机状态下的测量,获得了螺栓拧紧时及拧紧后轴向紧固力的数据。测量结果表明,和静态工况相比较,动态工况下螺栓轴向紧固力的衰减速度较快,残余力比值较小,即拧紧后螺栓轴向紧固力下降较多。

In order to do screw connection of metro-car door measurement of bolts and get the axial tightening force of bolt and change rule of axial direction tight force after tightening. A particular bolt strain-slice approach was calibrated, through demarcating bolt tensioner and high precision strain measuring device, got relationship between tight force and strain of bolt axial direction, and applied it practically to measure practical tightening and tightened axial-forces of bolts. The results showed that the axial tightened-force of bolt had very sharply attenuating speed in dynamic working state compared with static state, the axial force has a sharp decline after tightened, which leads to a low ratio of remained force, that is to say, axial direction tight force of bolt after tightening declined radically.