汽车侧滑检验台测量值的扩展不确定度评定

为了保证汽车侧滑检验台检测数据的准确可靠,本文对汽车侧滑检验台测量值的不确定度进行了分析、评定,供同行们共同探讨。     

汽车侧滑检验台示值误差测量结果的不确定度评定

本文介绍了汽车侧滑检验台示值误差测量结果的不确定度评定及其表示方法。     

侧滑检验台自动检定装置的不确定度评定

本文分析了侧滑检验台自动检定装置测量结果的不确定来源,并介绍了该不确定度的评定方法,仅供参考。     

侧滑检验台全自动检定装置的不确定度验证方法

侧滑检验台全自动检定装置是用于检定汽车侧滑检验台的标准器。本文针对原有的汽车侧滑检验台检定装置主标准器的不确定度验证方法,同时根据新研制的侧滑检验台全自动检定装置的工作特点,提出了一种将数显大量程千分表作为更高级计量标准,采用传递比较法的不确定度验证方法,仅供参考。     

机动车前轮侧滑检测不确定度评定

按照GB18565—2001和GB7258-2004标准规定的测试方法,建立了测量不确定度评定的数学模型,分析了测量过程中不确定度来源,并量化不确定度分量,对动态汽车前轮侧滑测量结果的不确定度进行了评定。     

平板式制动检验台示值误差测量结果的测量不确定度评定

文章主要参考JJF 1059—2012《测量不确定度的评定与表示》及JJG 1020—2007《平板式制动检验台》计量检定规程,对平板式制动检验台示值误差测量结果进行不确定度评定。     

浅谈检定中的滑板式汽车侧滑检验台示值误差的调整

滑板式汽车侧滑检验台（以下简称侧滑台）是测量汽车车轮在直线行驶过程中,车轮外倾角和前束的匹配情况,具体用侧滑量来表征。侧滑量是指汽车在没有外加转向力的条件下,低速直线行驶通过检验台时,滑板向内或向外的横向位移量与滑板的纵向长度之比值,侧滑量以m／km表示。根据中华人民共和国国家计量检定规程JJG 908-96《滑板式汽车侧滑检验台》中规定侧滑台示值误差不超过±0．2m／km。     

汽车悬架装置检测台示值误差校准结果的不确定度评定

本文根据汽车悬架装置检验台,结合JJF1192-2008(汽车悬架装置检测台》的要求,对汽车悬架装置检测台示值误差校准结果进行不确定度评定     

滚筒反力式制动检验台示值误差的测量结果不确定度

本文以JJG - 96所采用的测量方法为基础对滚筒反力式制动检验台的检定过程及其间产生的不确定度进行了分析、评定 ,得出了示值误差的测量结果不确定度     

滚筒反力式制动检验台示值误差测量结果的不确定度分析评定

滚筒反力式制动检验台(以下简称制动检验台)广泛应用于汽车修理厂和4S店,用于测量被检车辆的制动力。通过测定作用在测力滚筒上的车轮制动力的反力,结合已知的车辆轴载质量,实现车辆制动性能的检测。本文按照JJG906-2009的规定,对制动检验台示值误差的不确定度进行评定。制动检验台测试点为10000N时,示值误差为131N,扩展不确定度U=76N,k=2。     

加装放松板的滑板式汽车侧滑检验台可提高检测准确度分析

本文主要分析了由于汽车轮胎的形变及内向力因素对滑板式汽车侧滑检验台在检测汽车侧滑量时带来的影响。对加装放松板与未加装放松板的汽车侧滑检验台进行比较,从而推断加装放松板的滑板式汽车侧滑检验台更具合理性。     

A shear-deformable two-layer plate element with interlayer slip

A new finite element for two-layer plates with built-in interlayer slip is developed. The new plate element is based on a new plate theory formulated using a new variational principle due to Reissner. The accuracy of the new element is investigated by applying it to the problem of a two-layer plate with a linear slip law in cylindrical bending for which an exact elasticity solution exists. The comparison of the inplane response for several different values of interlayer shear stiffness and layer thickness ratios shows that the new element gives accurate results. The cylindrical bending of a two-layer plate with bilinear interlayer slip law is investigated with the new element and the results obtained are compared with a plane strain analysis. Good agreement is obtained for in-plane normal stresses and displacements. To further assess the simulation capabilities of the proposed element, a rectangular plate under concentrated load is analysed and the growth of slip failure regions is shown.     

生物安全柜的测量不确定度的评定

本文按JJG 1059. 1-2012《测量不确定度评定与表示》和CNAS-CL07∶2011《测量不确定度的要求》对耐压测试仪示值误差测得值的不确定度进行了评定。     

完善对滚筒反力式制动检验台的“检定”

分析了同一辆机动车在不同型号的制动台上由相同检验员检测,会得到不同的结果的原因。通过"机械"或"电子"方法对滚筒反力式制动检验台进行"模拟制动力"加载,经实验验证,是对滚筒反力式制动检验台原"静态检定"工作的一种有效、可靠的"完善"和"弥补"。通过"模拟制动力"加载试验,能发现滚筒反力式制动检验台或计算机联网中存在的问题。提出滚筒反力式汽车制动检验台在生产、使用中应注意的问题。     

雷氏夹膨胀测定仪测得值的不确定度评定

本文简述了雷氏夹膨胀测定仪的工作原理,依据JJG (交通) 093-2009《雷氏夹及雷氏夹膨胀测定仪》检定规程,结合具体检定过程,对雷氏夹膨胀测定仪的检定项目建立了测量模型,分析了测得值的标准不确定度分量来源,运用不确定度评定与表示方法,给出了雷氏夹膨胀测定仪测得值不确定度评定报告。     

机动车制动液蒸发损失测定的不确定度评定

蒸发损失作为机动车制动液的一项关键性能指标,其测量不确定度的评定对进一步优化测试方法,提高检测结果的准确性具有重要指导意义。本文采用自主研发的机动车制动液蒸发性能测定仪对某品牌HZY4型制动液样品进行测定,并评估测定结果中蒸发损失的不确定度,明确了仪器温控所引入的不确定度分量最大。因此,提高蒸发性能测定仪的控温精度,减小温度波动是减小测量不确定度的有效优化措施。     

X70管线钢洛氏硬度试验结果的不确定度评定

依据GB／T230．1—2009规定的试验方法,利用Wilson 2001T洛氏硬度计对某钢厂X70管线钢进行了洛氏硬度（HRB）试验,从试验重复性、硬度计复现性等多方面对洛氏硬度试验的不确定度来源进行了分析和阐述,对每个不确定度分量进行了逐一评定,最终给出了扩展不确定度及测量结果的不确定度报告。结果表明：该X70管线钢洛氏硬度测量平均值为（78．5±2．4）HRB,包含因子k=2。该方法对金属材料洛氏硬度的测量不确定度评定具有一定的参考价值。     

金属材料拉伸试验测试结果不确定度的评定

GB／T228．1—2010标准中修改了评定拉伸试验测量不确定度的方法。通过测定卷板的拉伸性能,对规定总延伸强度和抗拉强度的性能指标进行了测量不确定度评定,分析了不确定度来源,剔除测量结果中的离群值,提供了一种拉伸试验测量结果不确定度评定的可行方法,并对评定过程中的几个问题进行了探讨。     

Variability of Indentation Size Effect (ISE) of Standard Reference Block

The aim of the submitted work is to study the influence of applied loads ranging from 0.09807 to 0.9807 N on microhardness. Whereas standard reference block with defined specified hardness and its uncertainty was used as a specimen, individual measurement involved indirect calibration of tester. The measurement was repeated for estimation of the variability of results. The influence of applied load on the measured value of microhardness was evaluated by Meyer’s index n, PSR method and by analysis of variance and was different for individual “measurements” despite the identical specimen, method, equipment and appraiser. The uncertainty of measured values of the hardness partly obscures the occurrence and type of indentation size effect.     

A fast integral approach for drag force calculation due to oscillatory slip stokes flows

In this paper, we describe an efficient numerical method for modelling oscillatory incompressible slip Stokes flows in three dimensions. The efficiency is achieved by employing an integral approach combined with an accelerated boundary‐element‐method (BEM) solver. First the integral representations for slip flows with two different slip models are formulated. The resulting integral equations are then solved using the BEM combined with the precorrected‐FFT accelerated technique. 3D numerical codes have been developed based on the method described above. These codes are then used to calculate the drag forces on oscillating objects immersed in an unbounded slip flow. Three objects are considered, namely a sphere, a pair of plates and a comb structure. The simulated drag forces on these objects obtained from the two slip models are compared. In the sphere case, the simulated results are also compared with the analytical solutions for both the steady‐state case and the no‐slip oscillatory case and are found to be in good agreement. In addition, qualitative comparison of the simulation results with the experimental results in the plate problem is also presented in this paper. Copyright © 2004 John Wiley & Sons, Ltd.