环境温度变化压电智能骨料信号稳定性试验研究

Experimental Research on Temperature Stability of Piezoelectric Smart Aggregate Signals Under Environmental Temperature Change

研究了压电智能骨料在环境温度变化时的信号稳定性问题,并明确其变化规律及分析原因,为基于压电智能骨料的混凝土结构健康监测奠定基础。将预先埋设压电智能骨料的小尺寸素混凝土梁置入恒温试验箱中,改变箱内温度并记录不同温度下的压电智能骨料信号能量值,利用试验数据拟合出信号能量值与温度之间的关系。试验结果表明,压电智能骨料信号幅值受温度影响变化明显且表现出明显的非线性变化规律及符合压电材料机电耦合系数随温度变化的规律,其原因是由于压电陶瓷材料本身弹性常数随温度变化,并在宏观上体现为机电耦合系数的变化。

The signal stability of piezoelectric smart aggregates（PSAs）under environmental temperature changes is investigated to clarify the rules and its variation law is analyzed in this work.The research will lay a solid foundation for PSA-based structural health monitoring（SHM）.A small scale plain concrete beam pre-embedded with PSAs is placed and tested in a thermostatic chamber and the PSA signal energy values for changing temperatures are recorded,and the relationship between signal energy values and temperatures is fitted by the test data.The experimental results show that the PSA signals change obviously and behave significantly nonlinear property which complies with the electro-mechanical coupling coefficient of piezoelectric material.This is because the temperature change leads to the variation of elastic constants,reflecting the variation of electromechanical coupling coefficient on a macroscale.