大应变下贴片天线应变传感器的性能研究

Study on the Performance of the Strain Sensor under the Large Strain

基于微波贴片天线的应变传感器近年来在应变监测领域得到了广泛的研究和发展。由于天线特殊的力学性质——其谐振频率与天线的尺寸存在一定关系,即当天线经历应变时其尺寸发生改变,进而引起谐振频率的偏移,可将天线作为应变传感器的传感单元。理论推导和相关试验表明,在低应变下天线的谐振频率的偏移量与应变呈良好的线性关系,但在大应变时缺乏研究。通过设计试验将天线粘贴在钢板上进行大应变拉伸,试验结果显示在发生粘结破坏之前天线的谐振频率与应变同样具有较好的线性关系,且传感器的灵敏度与初始谐振频率十分接近,符合理论推导。

The strain sensor based on microwave patch antenna is presented to monitor structural strain. The resonant frequency of antenna will shift when dimension changes due to strain antenna experience. Taking advantage of this special mechanical property, the antenna can be used as strain sensing unit. Theoretically, the resonant frequency has good linearity with strain,which is validated by experiment under low strain level and lack of research when strain over 0. 1%. The experiment by stretching the steel plate on which antenna is attached is conducted. The results indicate that the relationship between resonant frequency and strain remains linear until connection damage,and the sensitivity is fairly close to initial resonant frequency,which is consistent with theory.