采用超声波法测量了螺栓应力，理论推导得出超声波声时差与应力之间的线性关系。通过制动器螺栓的声时差-应力关系的标定试验，可得到同型号螺栓的材料系数。提出在线实时检测风电机组螺栓轴向应力的方法，通过远程上位机操作界面可实现人机对话，完成螺栓应力从检测到预警的整个过程。

The ultrasonic wave was used to detect the bolt stress, and the linear relationship between the ultrasonic time difference and the stress was deduced theoretically. Through the calibration test of the relationship between acoustic time difference and stress of brake bolts, the material coefficients of the same type of bolts can be obtained. The method of on-line and real-time detection of bolt axial stress in wind turbine is proposed, and the man-machine dialogue is realized through the remote upper computer design operation interface, and the whole process of bolt stress detection and warning is completed.