桥梁应变采集系统设计及温度效应研究

Design of Bridge Strain Acquisition System and Study of Temperature Effect

针对工程中所使用的应变数据采集仪测量精度低、多为单点测量且接线复杂等问题,结合FPGA技术设计了一种基于振弦式应变计的桥梁应变采集系统,可同步采集8路应变数据,并优化了测频方法。同时依托山西省晋蒙黄河大桥实地监测,采用时变的平均值法研究应变及温度数据的变化规律,最终可对应变进行温度补偿来得到准确数据。实验结果表明:该系统测量误差小、采集效率高、接线简单、运行稳定,具有很高的应用价值。

Addressed in this paper are the issues of low measuring accuracy, single point measurement and complicated connection of strain gauge about data acquisition used in engineering. By utilization of FPGA technology, an acquisition system of bridge strain based on vibrating wire extensometer was designed, which can simultaneously collect 8-channel strain data, and the frequency measurement method was optimized. Meanwhile, on the basis of the field monitoring of Jinmeng Yellow River Bridge in Shanxi Province, the time-varying mean value method was adopted to study the variation law of strain and temperature data. Finally, the strain was temperature-compensated to obtain accurate data. The experimental results show that: the system has small measurement error, high acquisition efficiency, simple wiring and stable operation. The system has a high application value.