共查询到20条相似文献,搜索用时 171 毫秒
1.
2.
3.
针对光纤光栅(FBG)与被测金属构件可靠连接问题,提出环氧树脂掺金属粉末嵌入式封装技术,阐明了该封装工艺,采用纯弯曲梁对裸光纤光栅和封装后的光纤光栅分别进行应变实验,结果表明,经环氧树脂掺金属粉末封装后的光纤光栅传感器应变灵敏度是裸光纤光栅的1.3倍,达到1.53pm/με,具有很好的重复性,该方法提高了嵌入光纤光栅后被测金属构件的机械强度. 相似文献
4.
光纤Bragg光栅温度传感器封装方法研究 总被引:4,自引:2,他引:4
封装方法的研究对于光纤光栅应用于温度传感有着重要的意义.封装后的光纤光栅温度传感器必须具备良好的线性度和重复性.提出了一种使用细钢管进行封装的新方法.研究中发现,在封装时通过给光纤光栅施加预张力可以使封装后的光纤光栅温度传感器具备良好的重复性.实验表明:采用此方法封装的光纤光栅温度传感器具有良好的线性度和重复性,具有实际应用价值. 相似文献
5.
针对光纤光栅温度传感器的交叉敏感问题,提出了一种光纤光栅温度传感器的铝盒封装工艺,并对铝盒封装光栅温度传感器的温度和应力特性进行了理论分析和实验研究.研究表明,该封装有效地减小了光纤光栅的应变灵敏性,并将光纤光栅的温度灵敏度提高到裸光栅的1.8倍. 相似文献
6.
7.
8.
针对传统裸光栅直接粘贴式应变传感器应变灵敏度小的缺陷,提出了一种基片式光纤光栅应变增敏传感器,通过设计杠杆增敏结构的封装基片实现对光纤光栅的应变增敏.该传感器具有较大的应变放大机制,其测量精度与稳定性超过了裸光纤光栅.建立了该传感器的理论感知模型,并进行了与有限元仿真分析.由等强度悬臂梁标定实验可得该传感器实际应变灵敏度为6.122 pm/με,与理论结果和仿真结果一致,且线性度达到0.99998.通过动态激振实验对该应变增敏传感器的动态响应进行研究,实验结果表明该传感器能够在0~100 Hz范围内保持一致的增敏效果,能够良好的跟踪动态应变.该传感器在大型机械装备的健康监测与故障诊断方面具有良好的应用前景. 相似文献
9.
《传感器与微系统》2019,(6)
为满足海洋温深剖面连续拖曳测量的要求,测量海水深度的光纤布拉格光栅(FBG)压力传感器是利用FBG温补传感器来解决交叉敏感问题。由于二者对温度响应时间不一致,导致在中尺度旋涡、锋面等温度骤变海域测试海水压力时有所偏差。针对这一现象,设计出了一种新型的双光纤光栅压力传感器,通过在压力传感器的中心和边缘各封装温补和压力光纤光栅(边缘光栅不接触弹性膜片,仅受温度影响),使其对温度响应特性接近一致。实验测试结果表明:传感器的温补和压力光纤光栅对温度响应时间分别是1. 45 s和1. 52 s,响应一致性好。通过海试验证,FBG压力传感器与参考压力传感器ALEC—TD的相关系数高达0. 990 6,基本消除温度响应不一致导致的测量误差,能够达到准确测量压力的目的。 相似文献
10.
本文阐述了光纤光栅的制作方法、测温原理和温度特性,分析了光栅封装前后温度特性变化的原因;在实际温度测量的过程中进行必要的数据处理以及选择适当算法的必要性.给出了具体实验结果. 相似文献
11.
Magnetic fields are used extensively to direct liquid metal flows in material processing. Continuous casting of steel uses different configurations of magnetic fields to optimize turbulent flows in rectangular cross-sections to minimize defects in the solidified steel product. Realizing the importance of a magnetic field on turbulent flows in rectangular cross-sections, the present work is aimed at understanding the effect of a magnetic field on the turbulent metal flow at a nominal bulk Reynolds number of ∼5300 (based upon full duct height) (Reτ = 170, based upon half duct height) and Hartmann numbers (based upon half duct height) of 0, 6.0 and 8.25 in a 2:1 aspect ratio rectangular duct. Direct numerical simulations in a non-MHD 2:1 aspect ratio duct followed by simulations with transverse and span-wise magnetic fields have been performed with 224 × 120 × 512 cells (∼13.7 million cells). The fractional step method with second order space and time discretization schemes has been used to solve the coupled Navier-Stokes-MHD equations. Instantaneous and time-averaged natures of the flow have been examined through distribution of velocities, various turbulence parameters and budget terms. Spanwise (horizontal) magnetic field reorganizes and suppresses secondary flows more strongly. Turbulence suppression and velocity flattening effects are stronger with transverse (vertical) magnetic field. 相似文献
12.
Recently, people have begun to realize the importance of child‐resistant (CR) medicine packaging. However, most manufacturers and designers have not been able to effectively provide prevention strategies or design criteria to protect consumers. This research proposes a systematic approach to analyze CR packaging design problems and experiments to evaluate the identified design parameters and to generate the most suitable CR medicine packaging design. The design of a CR packaging bottle is used as an example to help explain the development procedure. During the development procedure, user trials, questionnaires, and children's anthropometric data on bottle opening and hand operations are analyzed. Five design parameters, specifically the cap diameter, cap height, bottle height, bottle diameter, and torsion, are identified and used to perform a Taguchi orthogonal array experimental analysis. A computer‐aided design system is also built to help generate the most suitable design alternatives. The results should assist designers in determining the most important CR design parameters and their most suitable combinations for bottle and related CR medicine packaging design. 相似文献
13.
1 Introduction A double-walled invertube is difficult to fabricate other than applying inversion process. Such kind of invertube can be used as impact energy absorbing element in transport vehicles, like aircrafts and automobiles. Reddy T Y[1] did the analysis of Internal inversion and calculated the inversion load. Reid[2] et al. examined nosing and internal inversion of cold drawn steel tube by the finite element package ABAQUS. Recently, Rosa P A[3] et al. investigated Internal invers… 相似文献
14.
张世超 《计算机与应用化学》1997,(2)
本文研究了固体硫酸盐摩尔热容Cp(T)的计算方法,提出物质热容可以由组成该物质的原子集团的热容贡献值求得,并根据实验数据计算得到了SO3原子集团对硫酸盐的热容贡献值Cp;SO3(T);根据稀土氧化物摩尔热容Cp,MnOm(T)和SO3的的热容贡献值Cp;SO3(T),本文计算得到了稀土硫酸盐的摩尔热容Cp(T)。 相似文献
15.
《Engineering Applications of Artificial Intelligence》2001,14(5):599-606
Cold bending of metal tube products is a metal forming process widely used in industry. With today's demand on high quality tube-dependent products, bending of tubing parts has become a precision metalworking operation that requires sophisticated knowledge and experience. In this work, a knowledge-based system (KBS) has been developed to aid the design of tube bending processes, including bending methods selection, tool/die design, and process parameters setup. The object-oriented programming techniques and the goal-driven search mechanism, featured by an interactive graphic user interface, have been applied in development of the proposed KBS. The system developed has shown effective in tube parts production with significantly reduced number of potential defects and failures, such as inaccuracy of bend angles or linear dimensions, wall thinning, flattening, wrinkling, twisting, dents or cracks, etc. 相似文献
16.
We present the first mass-flow sensor in silicon, based on the Coriolis-force principle. The sensor consists of a double-loop tube resonator structure with a size of only 9×18×1 mm. The tube structure is excited electrostatically into a resonance-bending or torsion vibration mode. A liquid mass flow passing through the tube induces a Coriolis force, resulting in a twisting angular motion phase shifted and perpendicular to the excitation. The excitation and Coriolis-induced angular motion are detected optically. The amplitude of the induced angular motion is linearly proportional to the mass flow and, thus, a measure thereof. The sensor can be used for measurement of fluid density since the resonance frequency of the sensor is a function of the fluid density. The measurements show the device to be a true mass-flow sensor with direction sensitivity and high linearity in the investigated flow range of as low as 0-0.5 g/s in either direction. A sensitivity of 2.95 (mV/V)/(g/s) and standard deviation for the measured values of 0.012 mV/V are demonstrated 相似文献
17.
Xiangwei Zhu Aslam D.M. Yuxing Tang Stark B.H. Najafi K. 《Journal of microelectromechanical systems》2004,13(3):396-405
To explore polycrystalline diamond (poly-C) as a packaging material for wireless integrated microsystems (WIMS), a new fabrication technology has been developed to fabricate thick WIMS packaging panels with built-in interconnects. An ultrafast poly-C growth technique, used in this study, involves electrophoresis seeding and filling of dry-etched Si channels by undoped poly-C followed by removal of Si. A second layer of highly B-doped poly-C, which acts as a built-in interconnect, is deposited on the backside of undoped poly-C layer. The lowest resistivity values demonstrated on control samples are in the range from 0.003 to 0.31 /spl Omega/-cm. The results show that, by increasing the poly-C growth areas through the use of 2-/spl mu/m-wide Si channels, the poly-C growth time can be reduced by a factor in the range from 2.75 to 10.5 depending upon the aspect ratio of Si channels. The poly-C packaging technology, which is expected to provide new structures/concepts in MEMS/WIMS packaging, is being reported for the first time. 相似文献
18.
We have developed a microphone package using flip chip technology instead of chip and wire bonding to create smaller MEMS
microphones. With this new packaging technology the transducer chip and an ASIC chip are flip chip bonded on a ceramic substrate.
The package is sealed by a polymer foil laminated over the chips and by a metal layer. The sound port is on the bottom side
in the ceramic substrate. In this paper the packaging technology is explained in detail and results of electro-acoustic characterization
and reliability testing are presented. We will also explain the way which has led us from the packaging of Surface Acoustic
Wave (SAW) components to the packaging of MEMS microphones. 相似文献
19.
20.
以半导体氧化物SnO2为基体材料加入40%的活性La2O3材料,制备出了对CO2具有敏感性的气体敏感材料,其检测体积分数范围为(0~5000) ×10-6.实验结果表明:在SnO2-La2O3敏感材料的基础上掺杂适量CeO2,Ag2O,SiO2等氧化物,不仅提高了其对CO2气体的灵敏度,而且可以提高其稳定性,从而大大改... 相似文献