压电智能骨料动态拉应力标定试验研究

Experimental Study on Dynamic Tensile Stress Calibration of Smart Aggregate

为了监测混凝土内部受拉开裂损伤,提出了混凝土内部拉应力监测压电智能骨料,并对其进行了动态拉应力标定试验研究。首先,制备4个压电智能骨料受拉试件,建立拉应力监测系统;其次,对压电智能骨料施加往复拉应力,标定得到其灵敏度系数;然后,对压电智能骨料试件施加单调荷载直至其受拉破坏,得到其抗拉强度及输出的电压信号,对比了破坏过程的实际与监测荷载。结果表明,往复荷载作用下,SA输出与输入荷载呈良好的线性关系,SA的灵敏度系数一致性较好;单调荷载作用下,各SA抗拉强度均高于混凝土抗拉强度。综上,压电智能骨料有潜力应用于混凝土内部的拉应力监测。

This paper proposed a smart aggregate(SA) sensor for tensile stress monitoring,which can be used to monitor tensile damage in concrete structures.The dynamic tensile stress calibration test was carried out on the sensors.Firstly,four test specimens with SAs were prepared and the tensile stress monitoring system was established.After that,cyclic tensile loads were applied on the SAs,and the sensitivities of SAs were obtained.Finally,monotonic loads were applied on the SAs till its failure.The tensile strength of SAs and their output voltages were obtained.The actual and measured loads were compared with each other.It can be found that there is a good linear relationship between the SA output and the applied load during cyclic reverse loading.Additionally,the sensitivities of SAs are in good consistence.The tensile strength for each SA is larger than the concrete tensile strength in monotonic loading.The test results indicate that the SA has the potential for internal tensile stress monitoring of concrete structures.