磁通量感測器應用於預力構材應力量測之研究

Stress Measurement of Pre-stressed Members Using Elasto-Magnetic Sensors

陳建州(Chien-Chou Chen) ； 吳文華(Wen-Hwa Wu) ； 魏端延(Duan-Yan Wei)

《中國土木水利工程學刊》 24卷2期 (2012/06) Pp. 157-167

https://doi.org/10.6652/JoCICHE.201206_24(2).0006

摘要

利用磁通量感測器來量測鋼纜索力或鋼鍵預力為近年來國內外開始嘗試的嶄新方法，其量測原理乃是建構於鋼材所承受的應力為直接影響其磁導率的主要敏感因素，所以藉由量測鋼材磁導率的變化便可從而計算出索力或預力值。但是由於鋼材應力並非決定其磁導率的唯一因素，且兩者之間的數學關係相當複雜，故磁通量感測器於工程應用上實際上仍存在許多問題值得進一步釐清與改善。因此本研究針對這項重點進行深入探討，經由實驗室中單股鋼絞線的量測分析來檢驗影響磁通量感測器量測準確性的各項可能因素及影響程度，並同時討論磁通量感測器的適用性。

關鍵字

磁通量感測器 ； 預力構材 ； 磁導率

並列摘要

The novel application of elasto-magnetic (EM) sensors to conduct the stress measurement of pre-stressed members such as stay cables or pre-stressed tendons has recently been adopted in several foreign or domestic cases. The feasibility of stress measurement with EM sensors is based on the fact that the subjected stress of steel material is the major parameter to influence its magnetic permeability. Consequently, the corresponding stress of a pre-stressed member can be determined by detecting the variation of its magnetic permeability. The stress of steel material, however, is not the exclusive parameter to control its magnetic permeability and their mathematical relationship can not be simply described. Due to these complexities, there still exist a number of problems requiring further clarification and improvement for the practical engineering applications of EM sensors. It is accordingly aimed in this study to explore these problems by investigating various possible factors to affect the accuracy of EM sensors with extensive measurements and analyses for a single tendon in the laboratory. The applicability and limits of EM sensors are also discussed based on these results.

並列關鍵字

Elsto-magnetic sensor ； Pre-stressed member ； Magnetic permeability