A technique to detect the bolt looseness in steel frame using the transfer impedance technique, which is a dual piezoelectric material technique, for bolted joint structural health monitoring is experimentally studied. An expensive impedance analyzer should be used to employ the single piezoelectric material technique (SPMT) while a general function generator and a digital multimeter can be used to employ the transfer impedance technique. Therefore, the low-cost fault detection could be carried out. A steel frame consisting of high tensile bolted connections with the splice angles was made, and the preload forces of the bolts were gradually reduced and the damage tests were carried out. The damage indexes were obtained using the transfer impedance technique and it was found that the fault existence of the bolted joint could be reasonably detected and the variations of the damage indexes tend to be increased as the degree of bolt looseness increases. The estimation results were similar to the results of the SPMT using the impedance analyzer. These results support that it is possible to estimate the bolt looseness of the bolted joint based on the impedance technique at low-cost, excluding an expensive impedance analyzer. It could be used effectively for bolted joint structural health monitoring if the study on identification of fault location and severity using the transfer impedance technique is supplemented in the future.

实验研究了一种利用转移阻抗技术（双重压电材料技术）检测钢框架中螺栓松动的技术，用于螺栓接头结构健康监测。应该使用昂贵的阻抗分析仪来采用单一压电材料技术（SPMT），而可以使用通用函数发生器和数字万用表来采用转移阻抗技术。因此，可以进行低成本的故障检测。制作了一个钢架，该钢架由高强度螺栓连接组成，具有接头角，并逐渐减小了螺栓的预紧力，并进行了破坏测试。利用传递阻抗技术获得了损伤指标，发现可以合理地检测出螺栓连接处的故障，并且随着螺栓松动程度的增加，损伤指标的变化趋于增大。估计结果与使用阻抗分析仪的SPMT的结果相似。这些结果支持，除了昂贵的阻抗分析仪之外，还可以基于阻抗技术以低成本估算螺栓连接的螺栓松动程度。如果将来增加使用转移阻抗技术识别故障位置和严重性的研究，则可以有效地用于螺栓连接结构的健康监测。估计结果与使用阻抗分析仪的SPMT的结果相似。这些结果支持，除了昂贵的阻抗分析仪之外，还可以基于阻抗技术以低成本估算螺栓连接的螺栓松动程度。如果将来增加使用转移阻抗技术识别故障位置和严重性的研究，则可以有效地用于螺栓连接结构的健康监测。估计结果与使用阻抗分析仪的SPMT的结果相似。这些结果支持，除了昂贵的阻抗分析仪之外，还可以基于阻抗技术以低成本估算螺栓连接的螺栓松动程度。如果将来增加使用转移阻抗技术识别故障位置和严重性的研究，则可以有效地用于螺栓连接结构的健康监测。