电阻应变计技术六十年（2）——电阻应变计敏感材料的发展（上）

敏感栅材料电阻应变计的关键元件，其性能将直接影响电阻应变计的各项特性，敏感材料的进展促进了电阻应变计的发展，本文主要介绍金属电阻合金，半导体，薄膜，厚膜等电阻应计敏感栅材料的进展，着重介绍各种金属电阻合金的主要性能。     

NiCrAlY薄膜应变计的研制

采用射频磁控溅射法在Ni基高温合金拉伸件上制备NiCrAlY薄膜应变计。研究了热稳定处理对NiCrAlY薄膜结构、表面形貌的影响,并且测试了NiCrAlY薄膜应变计的电学与应变性能。结果表明：热稳定处理后 NiCrAlY 薄膜应变计由于在表面形成了一层 Al2 O3膜,具有抗高温氧化的特性,在室温～800℃范围内,应变计电阻同温度呈线性变化,电阻温度系数（ TCR）约为290×10－6/℃,室温下的应变计系数（ GF）为2.1。     

超低温应用的电阻应变计研究

介绍可应用于液氮至液氦超低温度和超导磁体系统的电阻应变计的研究工作，主要是对超低温电阻应变计进行热输出，灵敏系数对强磁场效应等工作特性的实验研究。     

电阻应变计的温度效应及其消除方法

<正> 一、概述 电阻应变计是应变电测技术和应变式传感器必不可少的敏感元件。理想上,粘贴在试件上的应变计只响应施加在试件上的机械应变,而不受其它环境因素的影响。然而,同其它敏感元件一样,电阻应变计也并非尽善尽美。其一,应变计的电阻不仅随机械应变变化,而且随温度变化亦在变化(热输出);其二,应变计的灵敏系数,即电阻变化量与应变量之比本身也是温度的函数。这些温度效应如果不予以控制或消除,往往会带来显著的测量误差,有时甚至完全掩盖被测信号,而得出错误的结果。     

电阻应变计技术六十年（3）应变胶粘剂的进展

电阻应变计是借助于胶粘剂把试件应变传递到敏感栅上，引起电阻变化，这是电阻应变计和应变测量的重要组成元件，其性能影响和决定了电阻应变计的各项特性。本文主要论述应变胶粘剂６０年来发展概况及名类应变胶粘剂特性。     

混凝土应变计转换系数的测试方法研究

建筑工程检测领域常用混凝土应变计检测混凝土的结构应力应变,混凝土应变计的转换系数是影响检测结果准确度的重要参量.本文通过对振弦式应变计和电阻应变片式应变计的结构和检测原理进行分析,分别给出了对应的应变计转换系数测试方法,并列举了部分用到的标准器具     

多晶硅敏感技术(连载四)

<正> 5 多晶硅薄膜的压阻效应 目前,多晶硅薄膜在传感器上的应用主要有压力传感器、加速度传感器、应变计、热电传感器及执行器等。对于前几种可归结为力学量传感器,其理论基础是依据于多晶硅的压阻效应。     

中国微米纳米-PdCr薄膜电阻应变计研制及其高温应变敏感性能研究

在航空航天以及核电领域中,准确测量高温部件的应变、疲劳等结构参数十分重要,对满足高温应用环境的高温应变计需求非常迫切.在镍基合金基底上研制了PdCr薄膜电阻应变计,依次在基片上沉积NiCrAlY作为过渡层来增强附着性,沉积YSZ/Al2O3作为复合绝缘层满足绝缘性需求,溅射PdCr合金作为应变敏感层,并采用金属掩模对PdCr敏感层进行图形化,最后沉积Al2O3薄膜层作为高温保护层,并对PdCr薄膜应变计的应变敏感系数(GF)以及高温环境下的表观应变、漂移应变等性能进行了表征.结果表明,不同温度下PdCr薄膜应变计的电阻值随应变呈良好的线性关系;在常温下,其应变敏感系数为1.40;在800 ℃时,应变计的表观应变系数127 με/℃.应变计的电阻值随时间线性减小,导致的漂移应变约为1 800 με/hr,应变敏感系数为1.41.同时,对制备的PdCr薄膜应变计进行了可靠性评估和寿命评估.结果表明,其重复性测量误差约为5.71%,工作寿命超过10 h.     

电阻应变计技术六十年（一）：电阻应变计的由来,发展及展望

电阻应变计是目前世界上最常用的应力分析的敏感元件，也常用于制作传感器用测量诸如力（重量）、扭矩、压力和加速度等物理量。本文简要地介绍了电阻应变计６０年的发展历史，电阻就奕计的结构、分类及其现状，并展望了其发展趋势。     

氮化硅薄膜传感器的平面加工工艺研究

介绍一种以氮化硅薄膜为压力敏感膜、多晶硅为电阻应变计的压力传感器。该压力传感器先后采用2种不同的平面加工工艺进行加工,实际结果表明:改进后的工艺比较好。通过采用对称分布在一个敏感膜上的4只多晶硅电阻应变计串联组成惠斯通电桥的一个桥臂,减少桥臂电阻的制作误差。制作传感器样品并对传感器的电压输出特性进行了测试。测试结果表明:恒流激励的传感器的电压输出特性非常好,传感器具有过载保护功能。     

平膜片式薄膜压力传感器的线性度与灵敏度分析

针对薄膜应变片在圆平膜片上的两种基本布置方式，导出了平膜片式薄膜压力传感器的线性度和灵敏度的实用计算公式；分析了膜片的厚径比、薄膜应变比在膜片上的布置方式和位置对传器的线性度与灵敏度的影响，给出了部分研制的薄膜压力传感器的线性度和灵敏度的实测结果与理论计算结果的比较。     

Microfabrication and characterization of metal-embedded thin-film thermomechanical microsensors for applications in hostile manufacturing environments

Effective monitoring and diagnosis of manufacturing processes is of critical importance. If critical manufacturing process conditions are continuously monitored, problems can be detected and solved during the processing cycle. However, current technology still evidently lags behind practical needs. Microfabricated thin-film thermocouples and strain gauges are attractive for their small size and fast response. It is challenging to fabricate and embed these sensors into metallic components that are widely used in manufacturing. This paper investigates the fabrication, embedding, and characterization of metal embedded thin-film thermocouples and strain gauges. The materials (dielectric and metallic) constituting a complete microsensor were characterized and optimized. The results obtained from characterization and optimization of materials are presented and discussed. Thin-film thermocouples on stainless steel substrates (before and after embedding) were calibrated to elevated temperatures. The behavior of thin-film strain gauges was also studied. The metal embedded sensors demonstrated good accuracy, sensitivity, and linearity that matched the performance of commercial thermocouples and strain gauges well. The metal embedded microsensors are promising for in situ monitoring in hostile manufacturing environments.     

Quasi-static analysis of a face gear under torque

This paper presents a procedure for analyzing the instantaneous loaded contact of a face gear and its experimental validation. The gear can be straight or helical, with different axis angles and offsets. Several cutting and assembling errors are taken into account. The method is analytical and permits very fast computation of load sharing, including bending and contact effects. Experimental validation using strain gages was carried out.     

混合集成力敏传感器的研制

本文对半导体应变式传感器的非线性、温度零漂、灵敏度温度系数、蠕变等参数进行了研究,建立了电子线路综合补偿方法,并采用半导体平面工艺研制成功了小型硅应变片,与混合集成电路技术结合,使敏感元件与补偿、放大电路组合成为一体。     

基于粗糙集和贝叶斯的薄膜蒸发器参数评估

为了分析薄膜蒸发器过程参数对生产结果的影响,合理优化操作参数,结合粗糙集理论与概率论中的贝叶斯公式预测主要影响属性,提取评判规则。利用可辨识矩阵处理数据来过滤冗余属性,求得约简与核,再计算以综合决策、产量及蒸发强度作为结果属性的重要性,并引入贝叶斯公式计算其规则下的条件概率。计算结果表明,进料流量、进料温度、导热油温度和系统真空度对生产结果的影响最大,从而为工程应用编制软件提供参考。     

Least square method for the calculation of elastic constants

In this paper, a feasible formula is derived and simplified from least square method to calculate the elastic constants of materials. The simplified equation is identical to the stress and strain fluctuation formula obtained from statistical thermodynamics when the expression of the stress is redefined. It endues the formula with the theoretical validity. On the other hand, the convergence of the formula could be investigated via the theory of numerical analysis. Compared to the traditional fluctuation formula, the new technique shows better universality in the elastic bath method. Results obtained with a nearest-neighbor Lennard-Jones fcc crystal indicate that at low temperature the convergence of the formula is the same as the previous stress and strain fluctuation formula but the symmetry of the elastic constants is improved.     

Design and fabrication of a flexible three-axial tactile sensor array based on polyimide micromachining

This paper describes the design and fabrication of a flexible three-axial tactile sensor array using advanced polyimide micromachining technologies. The tactile sensor array is comprised of sixteen micro force sensors and it measures 13 mm × 18 mm. Each micro force sensor has a square membrane and four strain gauges, and its force capacity is 0.6 N in the three-axial directions. The optimal positions of the strain gauges are determined by the strain distribution obtained form finite element analysis (FEA). The normal and shear forces are detected by combining responses from four thin-film metal strain gauges embedded in a polyimide membrane. In order to acquire force signals from individual micro force sensors, we fabricated a PCB based on a multiplexer, operational amplifier and microprocessor with CAN network function. The sensor array is tested from the evaluation system with a three-component load cell. The developed sensor array can be applied in robots’ fingertips, as well as to other electronic applications with three-axial force measurement and flexibility keyword requirements.     

几何结构对复合薄膜巨磁阻抗效应的影响

复合薄膜的巨磁阻抗(GMI)材料的几何结构改变会对其GMI效应产生影响,实验已证实.但目前对GMI效应的理论尚不完善,缺乏对该现象的理论研究.通过经典电磁理论建立了复合薄膜结构的GMI效应的理论模型,并利用模型仿真不同结构参数下典型三层复合薄膜的GMI特性,系统研究了几何结构对复合薄膜GMI效应的影响,并得到结论:在复合薄膜结构中,存在一个最佳的导电层厚度,使GMI效应达到最强;导电层宽度的增加对GMI效应有增强作用.     

灰色神经网络仿真及其在MCMQC中的应用

为了解决大规模定制生产质量控制中质量数据缺乏的灰色不确定性问题,将灰色理论引入到了神经网络建模中.以灰色理论的核心思想(信息递阶、时变和多维特性)为基础,构造了基于灰色体系的建模方法,并对其进行了简化,给出了经过简化的一般性建模方法--横向、纵向和混合建模法,并将其与神经网络建模相结合.以一个典型的灰色BP神经网络为例,以横向建模方式对其进行了实现,并将其应用到大规模定制生产过程质量控制(MCMQC)中.仿真实验结果表明,灰色神经网络解决大规模定制生产质量控制中的灰色不确定问题是有效可行的.     

Dual-stage servo systems and vibration compensation in computer hard disk drives

This paper discusses two mechatronic innovations in magnetic hard disk drive servo systems, which may have to be deployed in the near future, in order to sustain the continuing 60% annual increase in storage density of these devices. The first is the use of high bandwidth dual-stage actuator servo systems to improve the precision and track-following capability of the read/write head positioning control system. The second is the instrumentation of disk drive suspensions with vibration sensing strain gages, in order to enhance airflow-induced suspension vibration suppression in hard disk drives.