水泥基传感器与混凝土的应变协调性分析

Strain compatibility analysis on cement-based sensors and concrete

为研究镍粉水泥基传感器应用于混凝土结构健康监测过程中传感器与周围混凝土的应变协调性,采用有限元软件ANSYS建立传感器与混凝土模型,计算改变传感器的埋设位置及偏斜角度、混凝土强度等级、荷载大小及类型等条件下传感器与周围混凝土的应力和应变值,并采用传感器与混凝土之间的应变相对差对它们之间的应变协调性进行分析.结果表明:传感器应埋设在应变均匀的中心区域,避免埋在表层;小角度偏斜对监测准确性影响不大;传感器应用于混凝土结构健康监测需综合考虑混凝土强度等级、荷载大小及类型等因素对监测结果的影响;应变相对差可以较好地反映传感器与周围混凝土的应变协调程度.

In order to study the strain compatibility of the nickel powder-filled cement based sensors and their surrounding concrete, the models of the sensors and concrete were set up by finite element software ANSYS. The stress and strain of the sensors and their surrounding concrete were calculated based on different embedded locations and angle deflections of the sensors, strength grades of concrete, and magnitudes and types of load. The strain compatibility of the sensors and their surrounding concrete were analyzed through the relative difference of strain. The results show that the sensors should be embedded in the internal homogeneous strain area of concrete members, rather than being embedded in the superficial area. The small angle deflection has little effect on the monitoring accuracy. As the sensors are used for health monitoring of concrete structures, the effect of strength grade of concrete and magnitudes and types of load should be systematically considered. The degree of strain compatibility of the sensors and their surrounding concrete can be better reflected by relative difference of strain.