压电埋入式混凝土应力及温度传感器

根据前期对埋入混凝土立方体模块中的压电陶瓷应力及温度特性，提出了一种旨在监测混凝土结构内部静应力及温度的压电埋入式应力温度传感器。该传感器以混凝土为基底材料，以压电陶瓷为敏感单元，通过测量压电材料中等效电路参数来反映混凝土结构中的静态或准静态应力及温度变化。同时，提出了一种新的方法来减小在传感器工作工程中由于应力-温度交叉传感导致的测量误差。该方法利用埋入混凝土中压电陶瓷材料特征频率对温度敏感而对应力不敏感的特性来修正等效电路参数的测量值。实验表明，这种方法可以将测量误差降低到5%以内，提高了测量的可靠性。为提高测量系统的通用性，并降低仪器系统的成本，建立了基于虚拟仪器方法的计算机数据采集、处理和分析传感器后端仪器系统。该系统集传感器标定、初始化、数据采集及结果显示为一体，能够高效地完成大量实际工程应用的需要。通过将该测量系统移植到笔记本电脑，还可以完成野外作业。

Piezoelectric-Embedded Sensor for Concrete Stress and Temperature

Based on the previous research on the stress and temperature characteristics of embedded piezoelectric ceramic, a piezo-embedded sensor was designed to monitor the stress and the temperature in concrete structure. This sensor utilized concrete as foundation material, piezoelectric ceramic plate as sensitive unit. According to the changes of the equivalent circuit parameters of the piezoelectric ceramic embedded in the concrete, the stress and the temperature of the concrete structure were obtained. A novel method was proposed to solve the problem of measuring error brought by cross sensitive of sensor to either stress or temperature. It is found that the characteristic frequencies are not sensitive to stress but have response to temperature. Such feature is supposed to solve the problem of measure error brought by cross sensitivity of stress and temperature. The experimental results show that the error is limited to 5% with the help of the characteristic frequencies. The measurement system was realized by the tool of virtual instrument. The data acquisition, initialization and signal proceeding systems were established in Labview program. Planting such virtual instrument system in laptop will make it possible to accomplish field operation.