水轮机上下蜗壳连接35CrMo钢螺栓,利用35CrMo钢螺栓的超声波声时比与轴向应力之间满足良好的线性关系这一规律,依据FPGA技术及数据算法,构建了一套24通道的超声波应力智能监测系统。该测定系统由一台超声波仪、24个压电式探头、一台通道转换器、一台显示和控制工控机组成,可同时检测24个螺栓的实时弹性应力,实现实时应力的测定。利用该系统进行了实际轴向应力的测定,结果表明,其误差完全可以满足工程要求。

The upper and lower volutes of the water turbine are connected with 35CrMo steel bolts. By utilizing the linear relationship between the ultrasonic acoustic-time ratio of 35CrMo steel bolts and axial stress, a 24 channels ultrasonic stress intelligent monitoring system was constructed based on FPGA technology and data algorithms. The system consisted of an ultrasonic instrument, 24 piezoelectric probes, a channel converter, a display and control industrial computer, It can simultaneously detect the real-time elastic stress of 24 bolts, achieving real-time stress measurement. And the actual axial stress was measured using this system, and the results showed that the error could fully meet the engineering requirements.