基于高频变压器拟磁饱和的磁致伸缩索力测量研究

发布时间：2019-02-20 10:10

【摘要】：钢缆索有着受力大、韧性好、硬度高、抗震能力强、重量小等特点,现已被长久的运用于工程设备(船舶、桥梁、建筑、水利)与民用设备(防护栏、楼板、地基)中。常见的钢缆索应用有:体育馆,斜拉桥,悬索桥,缆索护栏(边坡防护网)。在钢缆索使用过程中,它是承受中心的主力,是担负整个桥梁结构的重心。如果发生钢缆索受力过大、内部腐化、缆索自身故障、衰败等原因而使得钢缆索蹦裂,这必将酿成无法预料的恶果。因而,钢缆索的张力或是拉力都必须精而准的测量。另一方面,长久监测钢缆索的变化情况,既可以快速也可以准确的进行维护,也可使钢缆索在使用过程中,达到最大使用年限,提高其自身价值。因此,在线监测钢缆索索力是判定拉索结构稳固状态的有效方法,其中磁致伸缩索力测量法成为了国内外探究的重点。针对磁致伸缩索力测量的原理,现有研究者激励磁场强度的选取处于材料的最大磁导率附近。但实际上磁场强度处于最大磁导率附近所产生的信号变化小、磁导率变化小不利于实验的观察和实验结果的分析。因此磁场强度应选取在输出信号和磁导率的变化率最大的拟磁饱和区附近。此时常采用频率饱和的方式使其磁场强度工作在拟磁饱和区。为使频率达到饱和,常用高频变压器的方式来使其达到饱和。所以十分有必要建立基于高频变压器拟磁饱和的磁致伸缩索力测量的理论体系,完成基于高频变压器拟磁饱和磁致伸缩索力测量的拉力实验。本文在综合了目前国内外的索力测量方法的基础上,提出了一种基于高频变压器拟磁饱和磁致伸缩索力测量的方法,完成了基于高频变压器拟磁饱和磁致伸缩索力测量的理论研究,创建了实验方案与平台,完成了在交流激励方式下拉力实验研究。具体研究内容如下:(1)通过介绍常用钢绞线类型、实验所用钢绞线模型和磁导率变化量与钢缆索索力的关系,得到缆索索力与磁导率变化(35)?成正比,并对磁导率的测量进行了完善的推导。(2)论文阐明了高频变压器的特性,原理与理想模型。并对高频变压器拟磁饱和时的现象和磁饱和产生的原因进行进一步的推导。得出在高频变压器拟磁饱和状态下,如何进行磁化工作点的选取。(3)通过建立拟磁饱和的磁致伸缩索力理论模型,推导出缆索索力与温度,感应电压,材料磁导率,空气间隙等参数的关系。并在拟磁饱和状态下,总结了感应电压与拉力的关系,理论表明:在交流激励方式下,可通过测量输出感应电压求出加载拉力,并且感应电压与加载拉力近似呈线性关系。(4)设计了基于高频变压器拟磁饱和的磁致伸缩索力测量的拉力实验方案,完成了在交流激励方式下的拉力实验。用实验证实了感应电压与拉力基本呈线性关系。最后总结了全文和本文后续工作展望。
[Abstract]:Steel cables have been used in engineering equipment (ship, bridge, building, water conservancy) and civil equipment (fence, floor, foundation) for a long time because of the characteristics of large force, good toughness, high hardness, strong earthquake resistance and low weight. Common steel cable applications include: gymnasium, cable-stayed bridge, suspension bridge, cable fence (slope protection net). In the process of using steel cable, it is the main force of bearing center and the center of gravity of the whole bridge structure. If the steel cable is subjected to too much force, internal corruption, cable itself failure, decay and other reasons make the steel cable jump and crack, this will lead to unpredictable consequences. Therefore, the tension or tension of the steel cable must be measured accurately and accurately. On the other hand, monitoring the change of steel cable for a long time can not only quickly and accurately maintain the steel cable, but also make the steel cable reach the maximum service life in the process of using, and improve its own value. Therefore, on-line monitoring cable force is an effective method to determine the stable state of cable structure, and magnetostrictive cable force measurement method has become the focus of domestic and foreign research. According to the principle of magnetostrictive cable force measurement, the selection of magnetic field intensity is near the maximum permeability of the material. However, in fact, the signal produced by the magnetic field intensity near the maximum permeability changes little, and the change of permeability is not conducive to the observation of the experiment and the analysis of the experimental results. Therefore, the magnetic field intensity should be chosen near the quasi-magnetic saturation region where the output signal and the maximum change rate of permeability are obtained. In this case, frequency saturation is often used to make the magnetic field intensity work in the quasi-magnetic saturation region. To saturate the frequency, high-frequency transformers are often used to saturate them. Therefore, it is necessary to establish a theoretical system of magnetostrictive cable force measurement based on quasi magnetic saturation of high frequency transformer, and complete the tension experiment based on high frequency transformer quasi magnetic saturation magnetostrictive cable force measurement. On the basis of synthesizing the current cable force measurement methods at home and abroad, this paper presents a method based on quasi-magnetically saturated magnetostrictive cable force measurement for high-frequency transformers. The theoretical research on the measurement of magnetostrictive cable force based on quasi magnetically saturated magnetostrictive cable of high frequency transformer is completed, the experimental scheme and platform are established, and the experimental research of tensile force under AC excitation mode is completed. The specific research contents are as follows: (1) the cable force and magnetic permeability change are obtained by introducing the commonly used steel strand types, the model of the steel strand used in the experiment and the relationship between the change of magnetic permeability and cable force (35)? It is proportional to each other, and the measurement of permeability is derived. (2) the characteristics, principle and ideal model of high frequency transformer are expounded in this paper. The phenomenon of quasi-magnetic saturation in high frequency transformer and the cause of magnetic saturation are further deduced. It is concluded that how to select the magnetization working point under the condition of quasi magnetic saturation of high frequency transformer. (3) by establishing the magnetostrictive cable force model of quasi magnetic saturation, the cable force and temperature, the inductive voltage, the permeability of the material are derived. The relationship between air clearance and other parameters. In the condition of quasi magnetic saturation, the relationship between inductive voltage and pull force is summarized. The theory shows that the load tension can be obtained by measuring the output inductive voltage under AC excitation mode. And the inductive voltage is approximately linearly related to the loading tension. (4) an experimental scheme of magnetostrictive cable force measurement based on quasi magnetic saturation of high frequency transformer is designed, and the tension experiment under AC excitation mode is completed. The linear relationship between inductive voltage and tensile force is confirmed by experiments. Finally, the paper summarizes the full text and the future work of this paper.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG115.5

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