一种基于应变测量的放入式电子测压器设计

目的：设计一种新型的放入式电子测压器。方法：直接利用测压器的外壳来作为应变式压力传感器，代替了压电式压力传感器，结果：给出了这种传感器的灵敏度和动态响应频率。结论：这种基于应变测量的放入式测压器具有结构紧凑，成本低的优点。     

Strain Measurement in a Shape Memory Alloy with Strain Gauges

Abstract:  The recovery of shape due to temperature-induced martensite to austenite phase transformation in shape memory alloys (SMA), such as nickel titanium alloys, has been investigated and utilised in applications for many years. One of the problems in incorporating SMA in host materials, such as composites, is the poor bonding characteristics of the SMA. A closely related problem in experiments is the measurement of strains in SMA specimens; as thin wires have been used in many of the experimental investigations, strains have been deduced from length measurements. In the current work, electrical resistance strain gauges have been bonded on SMA strips. Tensile strains up to 8% during tensile loading as well as compressive strains during strain recovery due to subsequent heating have been measured. Strains determined by other methods, such as extensometer and length measurements, are also reported and compared. The major contribution of this work is the successful bonding of strain gauges on SMA and the measurement of large strains (up to 8%).     

压痕应变法测试车桥用钢的表面残余应力

采用压痕应变法分别对某车桥用钢在单矫和复矫(二次矫直)工艺条件下表面残余应力的分布情况进行了研究。结果表明:车桥用钢在剪切下料后出现的板形缺陷与钢板表面的残余应力大小和分布有直接关系,当表面残余应力或者正反面残余应力的差值较大时,钢板容易出现瓢曲等板形缺陷。这也说明了应用压痕应变法测试钢板表面的残余应力可以在剪板前有效地预测钢板变形情况,应用该技术可以有效地指导钢板轧制和矫直工艺的调整。     

Engineering Measurement and Testing of Land-based Structures Using Strain Gauges

This paper presents a number of case histories illustrating the benefits and costs of certain types of engineering measurement and testing, with a focus on strain‐gauged land‐based structures. The benefits are described mainly in terms of safety, economy and environment. The costs are related to the amount of data collected and processed. The paper concludes with some technical and financial guidance for clients, owners, consultants and contractors who may be considering these types of activities.     

对测量金属粘贴式电阻应变计电阻的误差分析

分析了测量应变计电阻的误差来源,给出了控制方法及专用工装示意图,并提出测量时注意事项。     

System of Strain and Load Measurement in Dynamic Testing of Materials

A multichannel system of high-speed recording of strains and loads during fracture toughness tests of materials has been developed. A four-channel analog-to-digital converter was used to record signals. Tests were carried out using a rotary and a vertical impact testing machines at various loading rates and temperatures. Some results are presented for impact testing of Charpy specimens with recording of load variation at supports during tests.__________Translated from Problemy Prochnosti, No. 3, pp. 140 – 145, May – June, 2005.     

Stiffness and Reinforcement Effect of Electrical Resistance Strain Gauges

Abstract:  The increasing use of low-modulus materials, on which the reinforcement effect of the electrical resistance strain gauge is not negligible, has re-opened the research interest into this issue. This study deals with the evaluation of stiffness, and of the strain gauge Young's modulus involved in the estimation of both the global and the local reinforcement effect; the relationship between the strain gauge stiffness and the local reinforcement effect is also analysed. In particular, the experimental technique used to determine the stiffness of some commercial strain gauges is described. The results show that the strain gauge stiffness alone does not permit an accurate evaluation of the local reinforcement effect.     

浅议应变式称重传感器零位偏移的调修

讨论应变式称重传感器零位偏移的原因：刚性体应力释放和过载。采用在测量桥路中并联电阻的方法,把输出电位拉偏,使零位恢复正常。     

千分表类量具示值误差测量值的不确定度分析

千分表类量具在机械加工行业中应用较为广泛,其示值的准确性直接关系到机械加工产品的质量,尤其是在大型精密轴类零件的加工过程中使用较多。本文就是以百分表类量具为被校准对象,通过对校准过程中测量结果的误差进行不确定度分析,以了解和掌握日常校准程中的误差来源,提高校准精度。     

塞尺厚度测量结果的不确定度评定

由于塞尺检定规程变更,本文对塞尺厚度进行了不确定度的重新评定,并给出了最佳测量能力.     

New Types of Resistance Strain Gauges Made of Semiconductor Whiskers

We created resistance strain gauges on the basis of threadlike semiconductor monocrystals of tellurium and selenium and investigated their deformation characteristics under uniaxial tension and compression (up to ± 2.6·10^–3) and hydrostatic pressure (up to 5·10⁸ Pa). Their characteristics are compared with the parameters of resistance strain gauges made of p-type silicon. We developed electric contacts for selenium crystals and concluded that resistance strain gauges are promising for investigation of composite materials under triaxial compression.     

The Reinforcement Effect of Strain Gauges Embedded in Low Modulus Materials

The reinforcement effect of electrical resistance strain gauges is well‐described in the literature, especially for strain gauges installed on surface. This paper considers the local reinforcement effect of strain gauges embedded within low Young modulus materials. In particular, by using a simple theoretical model, already used for strain gauges installed on the surface, it proposes a simple formula that allows the user to evaluate the local reinforcement effect of a generic strain gauge embedded on plastics, polymer composites, etc. The theoretical analysis has been integrated by numerical and experimental analyses, which confirmed the reliability of the proposed model.     

Cut‐off Frequencies Induced by the Length of Strain Gauges Measuring Impact Events

Abstract: The finite length of strain gauges may induce filtering effects when measuring impact events. In this study, we are interested in quantifying these effects. Precisely, we determined the cut‐off frequencies of strain gauges cemented on visco‐elastic bars and measuring impact‐induced strain waves. This study shows that the cut‐off frequencies increase with the bar’s wave velocity and decrease with the bar’s diameter. The asymptotic value, corresponding to an infinite bar diameter, is reached rapidly (bar diameter ≈ 15 mm). Moreover, we showed that the mode cut‐off frequencies are more severe (lower) than the gauge length cut‐off frequencies for bar diameters greater than 8 mm.     

Embedded Strain Gauges: Effect of the Stress Normal to the Grid

Abstract:  In general, a strain gauge embedded in a model is subjected to a stress normal to the grid, whereas a gauge on the external surface is free from such a stress. This paper concerns the effect of the stress normal to the grid on the output of the strain gauge; usually, the influence of such a stress has a negligible effect, however, in some cases a notable influence has been noted. Therefore, the output of the strain gauge is determined in function of the strains in the plane of the gauge, ɛ _l and ɛ _t, and of the stress, σ _n, normal to the grid. The analysis shows that the output of the strain gauge is influenced by the coupled effect of transverse sensitivity and pressure sensitivity of the strain gauge. In particular, the analysis shows that, for Constantan gauges compensated for steel, the influence of the transverse sensitivity is in general prevailing on that one due to the pressure sensitivity. The results reported in this paper explain the experimental data obtained by various researchers.     

一般压力表测量结果的不确定度评定

本文简要介绍了1．5级弹簧管式普通压力表测量结果不确定度评定的评定依据、环境条件、测量方法、数学模型、不确定度的来源以及扩展不确定度的评定。     

Modeling and Experimental Testing of Strain Gauges in Operational and Failure Modes

Strain gauges are resistive sensors bonded at critical locations on the surface of structural components to detect surface deformation and, thus, measure mechanical stress. However, strain gauges do not always report expected measurements, even under normal operating conditions. The primary goals of this paper were to develop predictive models for strain-gauge behavior and experimentally test them under controlled laboratory settings. A testing station was developed that generated a mechanical motion on a beam, subjecting strain gauges to a sinusoidally varying strain. Predictive models of the testing station were developed and experimentally analyzed. Models were also developed for two particular failure modes, namely, debonding and wire lead termination. For the cases studied, the models overpredict the output of a strain gauge operating under normal conditions, which is a discrepancy that can be explained by the gauge modifying the surface properties of the test component. Models for debonding and loose lead show agreement in terms of reduction in signal amplitude and histogram modification, respectively. Calculated and experimental data are presented that show characteristic signals in terms of time domain and histogram analysis.      

高密度栅测应变

将高密度光栅应用于力学参量的测量中。通过测得试件变形前后正交光栅衍射点阵的偏移移量，可逐点得到试件因载荷作用而引起的面内应变、离面位移和刚体传动分量。