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When a structure material is damaged by impact events, the reliability and lifetime of the material will be severely affected. So impact location is considered as the prime approach for structural health and damage monitoring. In this study, a novel fiber Bragg grating (FBG) impact location system based on broadband light source is designed, aiming at the shortcoming of existing location systems based on FBG. An improved localization algorithm based on the time difference of arrival (TDoA) is proposed for impact location. According to this algorithm, the impact position can be accurately predicted without wave velocity. Impact planar location experiments are carried out for verification of the FBG impact location system and algorithm on a400 mm×400 mm×3 mm aluminum alloy plate. The resulted locating error shows high precision and good stability of the proposed system. This work has been supported by the National Natural Science Foundation of China (Nos.61503218, 61403233, 61573226 and 61473176), the Excellent Young and Middle-Aged Scientist Award Grant of Shandong Province of China (No.BS2013DX018), and the Natural Science Foundation of Shandong Province for Outstanding Young Talents (No.ZR2015JL021). E-mail:pangdan@163.com 相似文献
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庞丹丹 《军民两用技术与产品》2015,(10)
随着民航业的高速发展,民航飞机维修的有效控制和管理成为了影响航空公司安全运营和持续发展的重要影响因素。目前国内很多航空公司都在尝试推进六西格玛管理的应用。从组织形式、项目管理等方面,甘肃维修部仍需要迈出更大的步伐本文在此背景下,分析探究可靠性管理及六西格玛管理方法在飞机维修中的运用,从组织形式、项目管理等方面为理论和现实发展做贡献。 相似文献
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应用改进支持度矩阵模型的光纤光栅高温传感系统 总被引:4,自引:4,他引:0
为了提高耐高温传感网络检测精度并优化其性能,针对传统光纤布拉格光栅(FBG)传感网络结构测量精度低及可靠性差的缺点,设计了一种高精度高可靠传感网络结构;并基于多传感器数据融合原理,构建了改进的支持度矩阵数据融合模型对初始采样值进行融合处理。实验结果表明,290℃时,应用改进的支持度矩阵模型的传感系统测温估计值总绝对误差为0.220℃,且估计值波动幅度较小;20~290℃范围内,系统精度达到±0.2℃;当传感器发生故障时,构建的支持度矩阵模型稳健性好,传感网络测温可靠性高。本文的高温传感系统具有精度高、可靠性好和抗干扰能力强等特点,适用于实际工程的温度测量。 相似文献
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基于一维稳态热传导理论提出环形热电发电器(ATEG)的数学物理模型,考虑P型和N型热电偶臂的构型尺寸、材料热电性质不对称性以及界面接触阻力对其输出性能的影响. 针对理想的环形热电发电器,基于最大能量转换效率原则建立P型和N型热电偶臂构型尺寸与材料性质间的最优定量关系. 考虑界面接触热阻和界面接触电阻效应的影响,给出相对于精确解更方便实用的电流线性简化解,确定环形热电发电器最大输出功率、最大能量转换效率对应的P型、N型热电偶臂圆周角度比. 发现界面接触对小尺寸器件的热电偶臂圆周角度比影响显著,但随着器件构型尺寸的增大,比值逐渐趋近于理想器件的结果.当器件尺寸参数sr>2时,可以基于理想模型指导环形热电发电器的设计计算. 相似文献
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为探究大叶种鲜叶原料的生化特性,本研究以云南大叶种(清水3号、香归银毫、云抗10号、云抗14号、云茶普蕊)的单芽、一芽一叶、一芽二叶、一芽三叶等不同嫩度的茶树新梢为研究对象,通过检测其主要滋味物质(茶多酚、黄酮苷、氨基酸及可溶性糖等)含量,探明不同品种云南大叶种鲜叶原料滋味品质随嫩度的变化规律,并运用多元统计方法研究不同嫩度鲜叶的分类,建立不同类别鲜叶的判别模型。结果表明,茶树新梢的成熟度越高,酚氨比、总简单儿茶素、黄酮苷、过氧化物酶等值越高(且一芽二叶和一芽三叶显著高于单芽和一芽一叶(P<0.05)),但没食子酸、氨基酸等值越低(且单芽和一芽一叶显著高于一芽二叶和一芽三叶(P<0.05));茶多酚、总酯型儿茶素、咖啡碱等值随着嫩度的降低先升后降,与一芽三叶相比,一芽二叶的茶多酚、总酯型儿茶素、咖啡碱等值分别增加了7.67%、13.77%、10.22%;黄酮苷和可溶性糖中含量较高的组分分别为芦丁、蔗糖,质量分数范围分别为0.03%~0.93%、0.14%~1.14%;单芽的云抗14号、一芽二叶的清水3号分别为适制绿茶、适制红茶的较佳原料;多元统计分析可把不同嫩度鲜叶分为单芽... 相似文献
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本文通过录像观察法、数据统计法、文献资料法对2013年全国大学生跆拳道锦标赛男子半决赛、决赛运动员使用下劈踢技术情况进行调查统计与分析,研究大学生跆拳道运动员下劈踢技术使用的方法和特点。 相似文献
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A relocatable resonant FBG-acoustic emission sensor with strain-insensitive structure 总被引:1,自引:0,他引:1
A novel resonant fiber Bragg grating (FBG) based acoustic emission (AE) sensor with relocatable, strain-insensitive and enhanced sensitivity structure is demonstrated for structure health monitoring (SHM) in this paper. With one end of the sensing FBG bonded to a polyimide (PI) plate acoustically the other end free, the sensor can be easily redeployed around coupled with the investigated structure via couplant and the monitored structure surface and get rid of the interference from the strain applied on the monitored structure. Experiment has been conducted to verify the characteristics of this FBG-AE sensor, whose results show that the sensor is insensitive to mechanical strain applied on the monitored structure. It is also shown experimentally that the sensitivity is enhanced by about 1.2 times than the conventiotlal design, while the novel sensor possesses good resonant frequency response to the standard AE waves. 相似文献