一种基于微带天线的应变测量技术

发布时间：2018-01-10 14:40

本文关键词：一种基于微带天线的应变测量技术　出处：《中国科学:技术科学》2014年09期 　论文类型：期刊论文

【摘要】：结构在长期使用中常常会产生裂纹,裂纹萌生时的尺寸一般很小,不容易被发现;当裂纹被发现时,往往已经扩展,甚至接近临界尺寸,危及结构安全.由于裂纹主要产生在结构的应变集中处,所以对"关键区域"的应变进行监测可以作为裂纹萌生的表征.传统的应变测量技术很难满足长时间、低成本、快速检测等要求.为克服传统应变传感器的缺点,本文对基于微带天线的应变测量技术进行了可行性探究.微带天线的中心频率与自身尺寸有关:当其变形时,中心频率也会发生相应的偏移.因此,可利用微带天线中心频率的变化来表征应变.本文设计和制作了四种不同尺寸的微带天线,以探究基于微带天线的应变测量技术,同时研究其影响因素.将天线黏附在悬臂梁上,并在悬臂梁自由端处施加载荷,进行应变测量实验.通过矢量网络分析仪得到回波损耗S11曲线,并获得应变与微带天线频率偏移的关系.分析结果显示,应变与中心频率偏移之间存在近似线性关系,可利用微带天线测量应变.
[Abstract]:Cracks often occur in the long service of the structure, and the size of the crack initiation is usually very small, so it is not easy to be found. When the crack is found, it has been spread, even close to the critical size, which endangers the safety of the structure, because the cracks mainly occur in the strain concentration of the structure. Therefore, the strain monitoring of the "critical area" can be used as the characterization of crack initiation. The traditional strain measurement technology is difficult to meet the long time and low cost. In order to overcome the shortcomings of traditional strain sensors, the feasibility of strain measurement technology based on microstrip antenna is explored in this paper. The center frequency of microstrip antenna is related to its size: when it is deformed. Therefore, the strain can be characterized by the variation of the center frequency of the microstrip antenna. In this paper, four kinds of microstrip antennas with different sizes are designed and fabricated. In order to explore the strain measurement technology based on microstrip antenna and its influence factors, the antenna is attached to the cantilever beam and applied the load at the free end of the cantilever beam. The S11 curve of echo loss is obtained by vector network analyzer, and the relationship between strain and frequency offset of microstrip antenna is obtained. There is an approximate linear relationship between the strain and the center frequency offset, and the strain can be measured by microstrip antenna.
【作者单位】：西安交通大学航天航空学院;海军航空工程学院青岛分院飞机教研室;机械结构强度与振动国家重点实验室;西安航空学院;
【基金】：国家自然科学基金(批准号:51175404) 西安莲湖区产学研项目(批准号:K2013-026)资助
【分类号】：TN822
【正文快照】： 1引言结构,包括桥梁、建筑、管道、飞机、车船、水坝等,在长期使用过程中往往会出现由于疲劳引起的裂纹.裂纹在使用中逐渐扩展,最终引起结构失效,造成巨大损失.如果能及早检测出裂纹并进行修复,那么将会避免很多事故的发生.传统的检测裂纹的方法往往费时费力、效率低下.例如,

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