逆磁致伸缩钢缆索索力传感器影响因素与传感特性研究

Steel cables have been more and more widely used in various large-scale structures of load-bearing building components，so the steel cable tension and its online monitoring methods are very important. The cable tension sensors and cable tension measuring methods based on villari-effect are becoming the researching hot of those skilled researchers. The sensing mechanisms,sensor's theory model, affecting factors and cable sensors' property need to be studied more deeply and imperatively. Cable tension sensor's theoretical model based on villari-effect is established in this project. The relationship between sensor output voltage and external force, between output voltage and excitation magnetic field, between sensor output voltage and material's temperature and the relationship between sensor output voltage and air gap clearance are also derived accordingly. Both sensors' influencing factors theories and simulated researching are also finished.The excitation magnetic field,material's temperature,material's permeability and air gap clearance influence on steel cable tension sensor property are researched separately. The senor's temperature influencing model is established and the temperature affecting mechanism is also finished. In addition, the appropriate temperature compensating method and error cancelling method are also proposed. Thirdly, two new kinds of cable tension sensors based on villari-effect are developed. Two experimental schemes and experimental systems are proposed and setted up both in impulse magnetic field excitation and in alternating magnetic field excitation.The magneto-elastic cable tension sensors' pull experiments,temperature affecting experiments and sensors' amplitude-frequency characteristic experiments are accomplished. When magnet field is pulsed magnet field or the alternating magnetic field with one frequency, the cable tension sensors' temperature property, stress property, pull experiments and measuring sensitivity are researched separately. Finally, the cable tension sensors' tension measuring experiments and preliminary using in practical bridges are finished.

钢缆索大量运用在各种大型受力结构，在线监测钢缆索索力尤为重要，其中逆磁致伸缩索力传感器及测量方法成为国内外研究热点。非常有必要研究基于逆磁致伸缩的钢缆索索力传感机理，对传感器的影响因素和传感特性进行深入研究。项目通过建立逆磁致伸缩索力传感器模型，推导输出感应电压与缆索索力、激励磁场、温度及空气间隙等物理量关系。通过研究激励磁化方式、温度、材料磁导率及空气间隙等因素对传感器的影响，完成传感器的影响因素理论分析、仿真及实验研究。建立传感器的温度影响模型，完成影响机理研究，提出合适的温度误差消除方法。研制出两种新型结构的缆索索力传感器，设计实验方案，搭建实验系统对传感器进行一系列实验，包含温度影响、幅频特性实验及不同磁化方式下的外力加载实验。探索交流激励下传感器的幅频特性。重点分为脉冲和交流激励下，研究传感器的温度特性，力学特性及索力测量灵敏度，最后完成传感器工程现场索力测量实验及初步应用。

钢缆索具有承力多、质量小、尺寸紧凑、柔性好等优点，被广泛应用于船舶、护栏、桥梁、铁塔等各种民用基础设施、工程机械、现代工程等大型设备中,例如（体育馆，电影院的拉索，斜拉桥，悬索桥，缆索护栏（边坡防护网））。由于钢缆索在使用过程中作为承受重力或是拉力的关键，一旦由于过载，腐蚀，风化或是本身的失效，衰退而产生断裂,将可能造成难以估量的后果，所以钢缆索的张力必须准确的测量。另一方面，长期监测钢缆索的变化情况，可以准确、快速的进行维护，使钢缆索达到最大使用年限，提高它的自身价值。因此，对钢缆索进行受力检测是评价拉索结构安全状况的有效手段。.项目首先，建立了逆磁致伸缩测量索力的钢缆索的理论模型和传感器模型，推导了相关受力与激励磁场，温度，材料磁导率，空气间隙等参数的关系。其次采用套筒式传感器结构，利用电磁场仿真软件仿真了相关的参数设置，并用试验方式实际测试了该结构，结果并不理想，但在此基础上提出了一种新型的基于磁饱和逆磁致伸缩式套筒传感器测量索力传感器，分析了原理，推导了饱和时感应电压与拉力的关系，进行了相关的实验测试，初步验证了该方式的可行性，同时结合目前流行的旁路激励存在的磁路不连续的耗损，结合工程实践，提出了插针式套筒传感器模型，方便工程应用。. 另外，在研究过程中，发现采用高频电磁波在钢缆索上传播时形成驻波的方式来电化缆索受力，由于钢筋的磁导率具有逆磁致伸缩效应，电磁波在其中的传播速度、波长以及相位都因受力引起的磁导率变化而发生相应的变化，钢筋作为终端开路的导体，电磁波在终端会发生反射，形成驻波，驻波的形成能放大因受力变化所引起的电磁波驻波电压变化，把受力大小直接表现在端电压变化上，实现受力的电化表示，项目研究推导了该方法的原理，采用等效模型方式理论验证了方法的正确性，并通过实验测试，结果说明该方法具有可行性。.项目目前已发表文章4篇，已投文章1篇，拟投文章2篇，申请发明专利3项，获得发明专利受权2项。.