基于压电波动法的混凝土裂缝损伤主动被动监测对比试验

Contrast Tests for the Active and Passive Monitoring Technologies of Concrete Crack Based on Piezoelectric Wave Method

目的对基于压电波动法的混凝土裂缝损伤主动与被动监测方法进行对比研究,探索两种方法的特点以及适用范围.方法将压电陶瓷传感器埋置在两个完全相同的混凝土柱内,两试件分别承受小偏压和大偏压荷载.同时应用主动和被动损伤监测技术对两试件的破坏过程进行监测.结果在被动监测试验中,小偏压试件所释放出的声发射信号能量为大偏压试件的14倍.从能量释放在时长上的分布比重看,小偏压试件在达到极限荷载前就已经释放了80%以上,而大偏压试件只释放不到40%;在主动监测试验中,大、小偏压试件的最终损伤指数分别为78.8%和68.6%.结论被动监测技术能有效反映出试件所受荷载及破坏过程的特点,主动健康监测技术能有效地识别结构处于不同的健康状态,两种方法的特点形成互补.

Contrast tests were developed for the active and passive monitoring technologies of concrete crack based on piezoelectric wave method. The characters and applied ranges of two methods were explored. The piezoceramics transducers were buried into two same concrete columns which bearing small and large eccentric compression respectively. The failure process of specimens was monitored by both active and passive ways. The relationship between test phenomena and results were researched. About passive monitoring test, the energy of acoustic emission signals released from small eccentric compression specimen is 14 times the large eccentric one; about active monitoring test, the damage indexes of two specimens are 78.8% and 68.6% ,respectively. Test results show that：the passive monitoring method can reflect the characters of load and failure process, the active monitoring method can reflect the damage degree of specimens. Two methods can complement each other.