拉力试验机同轴度校准技术研究

从同轴度棒材料、试验载荷、校准方法、装配方式、加荷速率、机械偏心距等几个方面，对影响同轴度测量结果的因素进行分析，结果表明：同轴度的三种测量方法中，应变片法优于引伸计法优于几何法；各影响因素按影响程度由大到小依次为：机械偏心距、装配方式、同轴度棒材料、校准方法、加荷速率；同轴度随着机械偏心距的增加逐渐增大，随着试验载荷的增加逐渐减小，随着同轴度棒材料弹性模量的增加逐渐增大，随着加载荷速率的增加逐渐增大；装配方式对同轴度的影响按程度由大到小依次为：螺纹夹具、圆棒夹具、带万向结构的夹具。

Research on Coaxiality Calibration Technology of Tensile Testing Machine

The affecting factors on the coaxiality measurement results were analyzed，including coaxiality bar material，test load，calibration method，assembly mode，loading rate，mechanical eccentricity，etc.The results indicated that among three measurement methods of coaxiality，the strain gage method was best，followed by extensometer method and geometric method.The influence sequence of each factor ranked as:mechanical eccentricity，assembly mode，coaxiality bar material，calibration method，loading rate.The coaxiality was increased with an increase in mechanical eccentricity，elastic modulus of coaxiality bar material and loading rate，while decreased with the rise of test load.The influencing order of assembly mode on coaxiality was the thread fixture，round bar fixture and the fixture with universal structure.