通过对螺栓的轴向应力检测模型进行优化处理,直接建立了螺栓轴向应力与纵波、横波渡越时间比的平方的关系。优化后的模型能同时修正温度的影响,模型中各项参数只与螺栓的材料、温度变化有关。利用8.8级M20×130螺栓的各项拟合参数,对其自身、同型号、同材料螺栓在0~300 MPa,0~40 ℃的应力检测精度与温度修正进行验证。结果表明其自身应力检测与温度修正误差分别为0~15.1 MPa,3.31~10.22 MPa;同型号螺栓的应力检测误差为1.1~24.3 MPa;同材料螺栓的两种误差分别为1.9~26.9 MPa,3.25~19.03 MPa。 这说明优化后的模型具有足够的可靠性且适用于同材料螺栓的轴向应力评估与温度影响修正,在工程应用中能有效提高工作效率。

The relationship between axial stress and the square of the ratio of longitudinal and transverse wave transit time is directly established by optimizing the axial stress detection model of bolt. The optimized model can correct the influence of temperature at the same time. The parameters in the model are only related to the changes of bolt material and temperature. Using various fitting parameters of the bolts of grade 8.8 M20×130, the stress detection accuracy and temperature correction of bolts of the same type and material at 0-300 MPa and 0-40 ℃ are verified. The results show that the errors of stress detection and temperature correction are 0-15.1 MPa and 3.31-10.22 MPa respectively, and the stress detection error of bolts of the same type is 1.1-24.3 MPa. The two errors of bolts with the same material are 1.9-26.9 MPa and 3.25-19.03 MPa respectively. The results show that the reliability of the optimized model is sufficiently high and it is suitable for axial stress evaluation and temperature influence correction of bolts of the same material, which can effectively improve the work efficiency in engineering application.