压力传感器最小二乘直线不确定度评定及应用

主要介绍压力传感器最小二乘直线不确定度的评定方法,并结合试验数据,对测量结果不确定度和最小二乘直线不确定度进行了比较及说明。     

圆度误差测量结果不确定度的评定

本文探讨了应用三坐标测量机测量圆度误差时其测量结果的不确定度的分析与评定。在做精密测量时,测量结果的准确性评价,国际上推荐使用测量不确定度作为度量尺度。为判定测量结果的准确性,有必要对圆度测量结果进行不确定度的评定。     

数字测温仪温度修正值校准结果的不确定度分析

文章对测量范围在0～100 ℃,分度值为0.1℃的数字测温仪的示值修正值的扩展不确定度进行了评定,在100℃时温度修正值的扩展不确定度为0.08℃.     

最小二乘测量结果不确定度的评定及案例

本文给出了测量值服从正态分布且相互独立的最小二乘测量结果扩展不确定度评定公式,以及实际应用案例,弥补了《测量不确定度表示指南》＾［１、２］（简称“指南”）在该问题表述上的不足。     

电子秤化整前修正误差的测量不确定度评定

依据JJG539-1997《数字指示秤检定规程》检定电子秤(以下简称秤)；依据JJF1059-1999《测量不确定度评定与表示》评定被检秤化整前修正误差的不确定度。     

工作用玻璃液体温度计修正值测量值的不确定度评定

本文按照JJG130-2011的规定,对工作用玻璃液体温度计修正值的不确定度进行评定。温度计测试点为0℃、10℃、20℃、30℃、40℃、50℃时,修正值分别为+0.04℃、-0.03℃、-0.04℃、0.00℃、+0.02℃、0.00℃,扩展不确定度U=0.07℃,k=2。     

模拟式电压表测量值的不确定度评定

依据JJG124-1993的6.3.3.1用数字表作为标准的检定方法对模拟式直流电压表测量值进行了不确定度的分析和评定。     

工作用玻璃液体温度计示值修正值不确定度分析评定

该文根据JJF 1059.1—2012《测量不确定度评定与表示》和JJG 130—2011《工作用玻璃液体温度计检定规程》,对工作用玻璃液体温度计示值修正值的不确定度来源进行了分析,利用一支分度值为0.1℃,温度范围100℃～150℃的玻璃液体温度计,介绍了温度计示值修正值的不确定评定的方法,并对测量结果不确定度评定的步骤进行了详细的说明。     

基于蒙特卡罗方法的平面度测量不确定度评定

介绍利用蒙特卡罗方法进行平面度测量的不确定度评定.首先,根据最小二乘法得到平面度的误差模型,再采用蒙特卡罗仿真方法对测量值进行模拟仿真,从而得到平面度误差的不确定度,然后将评定结果与传统评定方法的结果进行比较.结果表明该方法简便易行.     

酒精计修正值的不确定度评定

浮计检定采用直接比较法,将二等标准酒精计与被检酒精计同时浸入同一检定液中,直接比较它们标尺的示值,从而得到被检酒精计的修正值。影响酒精修正值的不确定度因素有二等标准酒精计组、被检酒精计读数、检定液体毛细常数变化、被校干管不垂直及分度线倾斜、测量重复性。本文通过对这几方面的分析,从而评定酒精计修正值的不确定度,对日后的计量检定提供一些参考。     

The application of direct orthogonal signal correction for linear and non-linear multivariate calibration

Traditionally, the direct orthogonal signal correction (DOSC) is always used together with a latent variable method such as partial least square (PLS) or principal component regression (PCR), to build a linear calibration model. In this study, PLS and least square support vector machine (LSSVM) were used to develop the linear and non-linear relation between spectra and components, respectively. DOSC was used to preprocess the input data, and the effect of DOSC pretreatment on linear and non-linear calibration model was investigated. The experiment was performed with three data sets. The first one was the acousto-optic tunable filter near infrared (AOTF-NIR) spectra of apples, the second one was the temperature-induced spectra of a ternary mixture of ethanol, water and 2-propanol, and the third one was the NIR spectra of corn. For all of the applications, the relation between spectra and components can be clearly observed in the spectra plot or the score plot after DOSC pretreatment. DOSC improved the predictive ability of PLS model. However, DOSC removed useful non-linear information that was related to components, thus, was not able to improve the performance of LSSVM model. DOSC pretreatment seems to be not suitable for non-linear calibration.     

A method for the preliminary design of gears using a reduced number of American Gear Manufacturers Association (AGMA) correction factors

Typically, the preliminary design of mechanical components such as gears is carried out using standardized design processes such as those developed by the American Gear Manufacturers Association (AGMA). These design standards include a large number of ‘correction factors’ to account for various uncertainties. As the knowledge about these uncertainties increases, it becomes possible to include them systematically in the design procedure, thereby reducing the number of empirical correction factors. Robust design provides a way to design in the presence of various uncertainties. In this article, a design method is proposed to eliminate empirical correction factors and is demonstrated by eliminating two correction factors from the AGMA design standards for a spur gear, namely, the factor of safety in contact and the reliability factor by the formal introduction of uncertainty in the magnitude of load and material properties. The proposed method is illustrated with the design of an automotive gear with desired reliability, cost and robustness.     

测功机转矩示值误差测量结果的不确定度评定

本文主要根据JJF 1059-1999测量不确定度评定与表示计量技术规范，对测功机转矩示值误差的测量结果进行不确定度评定。通过评定，以此作为对相同情况下的测功装置进行测量不确定度评定的一种模式，以便于今后工作的开展。     

On the correction of plasticity effect at the hole edge when using the centre hole method for measuring high welding residual stress

Significant error caused by plasticity at the hole edge may arise when measuring sufficiently high welding residual stress by means of the hole drilling method. According to elastoplastic theory, a critical parameter of plastic deformation round the centre hole is obtained. On the basis of this critical parameter, a simple method is proposed to correct the stresses for the plasticity effect. It is shown in the experiments with welded joints that the correction method may improve the accuracy of high residual stress measurement.     

A method for the evaluation of regular components of the stress field in the plastic zone near the tip of a mode-I crack

We propose a method aimed at the evaluation of the amplitude of singularity and dimensionless angular distributions of the second terms in the expansions of stresses, strains, and displacements in the plastic zone in the vicinity of the crack tip. The method is based on the combination the Hutchinson-Rice-Rosengren-type analytic solution and a numerical solution obtained by using a modified method of boundary layer. The presented results enable us to analyze the effects of constraints in broad ranges of conditions of biaxial loading. __________ Translated from Problemy Prochnosti, No. 3, pp. 43–59, May–June, 2006.