【正文】 已經(jīng)有很少人對(duì)技術(shù)問(wèn)題和在實(shí)驗(yàn)條件下如何處理測(cè)量的不確定性值和如何從測(cè)量的不確定性值可以學(xué)到什么感興趣了。所有的參加者都用液壓疲勞機(jī)，測(cè)量模型是由鋼制成的，它的表面的壓力范圍是 375390Mp,拉伸力壓強(qiáng)的范圍是 。實(shí)驗(yàn)室 3：報(bào)告并沒(méi)有包括不確定性的值，但是，給出了機(jī)器的精度，在實(shí)驗(yàn)中誤差被控制在一個(gè)具體的范圍之內(nèi)，測(cè)量了一個(gè)模型的彎曲壓 力，但是它們對(duì)疲勞結(jié)果的影響并未考慮。因?yàn)檫@個(gè)測(cè)試的目的是統(tǒng) 計(jì)一個(gè)由顧客指定的實(shí)驗(yàn)所發(fā)生一些特殊的誤差。并不是所有的疲勞實(shí)驗(yàn)都是這樣的，因此，研 究一下實(shí)驗(yàn)的 參與者如何處理測(cè)量的不確定性值是必要的。 結(jié)論 ： 在參與者中定義、計(jì)算、解釋測(cè)量的不確定性值的方法和使用 Whole圖表的方法很難讓人明白，即使實(shí)際上它們是疲勞實(shí)驗(yàn)的重要的組成部分，并且它們有一些也是可以接受的。 不確定性數(shù)值 ： 所有的實(shí)驗(yàn)室都考慮到了測(cè)量的不確定性值，但是沒(méi)有一個(gè)能確定測(cè)量的不確定性值而只是考慮了它的影響。另一個(gè)問(wèn)題就是計(jì)算圖表的數(shù)學(xué)方法，用普通的方法和參照 ASTM標(biāo)準(zhǔn)，圖表應(yīng)該盡量使圖表的空間錯(cuò)誤最小化，例如，統(tǒng)計(jì)模式是 log log logN a b S ?? ? ? (1) 假定 ? 是一個(gè)任意的錯(cuò)誤，結(jié)果就有一個(gè)固定的變化，也就代表一個(gè)以 10為底的對(duì)數(shù)，? 能夠解釋至少兩種錯(cuò)誤：即 (1)由于材料性質(zhì)的 分散導(dǎo)致的錯(cuò)誤， (2)由于測(cè)量程序的不確定性而導(dǎo)致的錯(cuò)誤。 實(shí)驗(yàn)室 1：不確定性值是由于所用的壓力把承載單元和空間不確定性值也考慮了進(jìn)去。這就是客戶要求的測(cè)量。實(shí)驗(yàn)結(jié)果表明大量的測(cè)量不確定性結(jié)果是可以計(jì)算和報(bào)告的。沒(méi)有實(shí)驗(yàn)室包括最重要的不確定源，當(dāng)它們進(jìn)行不確定值的計(jì)算時(shí)，有幾個(gè)實(shí)驗(yàn)室沒(méi)有計(jì)算符合從指導(dǎo)到結(jié)果的測(cè)量的不確定性值。 這種測(cè)量結(jié)果被用來(lái)計(jì)算兩個(gè)物體的疲勞增長(zhǎng)的參數(shù)， A 和 B,和由于測(cè)量錯(cuò)誤而引起的不確定性值，報(bào)告的結(jié)果應(yīng)該包括 A和 B的結(jié)果和這種不確定性值，在結(jié)果的后面尤其是這些不確定性值每個(gè)模型的這幾種 特性都應(yīng)該報(bào)告。數(shù)學(xué)公式是根據(jù) GUM 來(lái)計(jì)算的，模型的溫度可以測(cè)量，但是它們很容易被忽視。 不確定性和實(shí)驗(yàn)室的處理： 所有實(shí)驗(yàn)結(jié)果和用普通方法計(jì)算的維勒?qǐng)D如圖 2所示： 圖 2 所有實(shí)驗(yàn)結(jié)果和用普通方法計(jì)算的維勒?qǐng)D 所有實(shí)驗(yàn)結(jié)果和用普通方法計(jì)算的維勒表如表 1所示： 表 1 所有實(shí)驗(yàn)結(jié)果和用普通方法計(jì)算的維勒表 有一個(gè)實(shí)驗(yàn)室做了相反的結(jié)論，例如用對(duì)數(shù)表示壓力值，這可能導(dǎo)致如上表所示的空間的誤差。沒(méi)有人考慮到非實(shí)際的測(cè)量的不確定性值的因素，這是基于實(shí)驗(yàn)得出的。一個(gè)重要的問(wèn)題是這些實(shí)驗(yàn)室僅僅包括了那些容易包括的測(cè)量不確定性值的來(lái)源，例如刻度表上的一些刻度誤差。對(duì)一個(gè)測(cè)量的不確定性值的估計(jì)和在壽命的 30%的變化量中和材料變化量的范圍中，因此，結(jié)論就在這個(gè)實(shí)驗(yàn)中，材料的測(cè)量不確定性值在這個(gè)實(shí)驗(yàn)中可以忽略不記。維勒?qǐng)D表表明，差異是由不同的圖表模型造成的。實(shí)驗(yàn)室 2：報(bào)告并沒(méi)有包括不確定性的值，載荷單元的不確定性值和微小誤差被考慮了，但是忽視了大的分散的材料，模型溫度被測(cè)量了，模型制造方法也被考慮到了，關(guān)于載荷類型的問(wèn)題沒(méi)有考慮。做這個(gè)測(cè)量時(shí) ASTM E4669 ISO57252.、 ASTM E46696并沒(méi)有考慮到測(cè)量的不確定性值，由于誤差不能超過(guò)最大和最小值的范圍的百分之五，所以， ASTM46696參照彎曲壓力，對(duì)模型的測(cè)量也有一些精度要求。關(guān)于測(cè)量的不確定性值的討論和鑒定與這個(gè)問(wèn)題息息相關(guān)。 However, ASTM E46696 mentions that the bending stress introduced owing to misalignment must not exceed 5% of the greater of the range, maximum or minimum stresses. There are also requirements for the accuracy of the dimensional measurement of the test specimen. All participants used hydraulic testing machines. The test specimens were made of steel (yield stress 375–390 Map, and tensile strength 670–690 Map, tabulated values). The test specimens were distributed to the participants by the organizer. Results The primary laboratory results that should be pared are the estimated Whaler curves. In order to present all results in the same way, the organizer transformed some of the results. The Whaler curves reported by the participants are shown in Fig. 1. It can be seen that there are considerable differences between laboratories. An approximate statistical test shows a significant laboratory effect. Material scatter alone cannot explain the differences in the Whaler curves. In order to investigate if the laboratory effect was solely caused by the modeling uncertainty, we estimated new parameters from the raw data with a mon algorithm. We then chose to use only the failed specimens and to make the minimization in the logarithmic life direction. The results are shown in Fig. 2. A formal statistical significance test was then made, and the result of such a test shows that the differences between the laboratories shown in Fig. 1 could be attributed only to modeling. Uncertainty of measurement calculations One of the most important objectives with this investigation was to pare the observed differences between laboratory test results with their estimated uncertainties of measurement. The intention was to analyze the uncertainty analyses as such, and to pare them to the standard procedure remended in the ISO guide: Guide to the Expression of Uncertainty in Measurement (GUM) [1]. The laboratories identified different sources of uncertainty and treated them in different ways. These sources are the load measurement, the load control, the superimposed bending stresses because of misalignment and the dimensional measurements. Implicitly, laboratory temperature and humidity, specimen temperature and corrosion effects are also considered. In addition, the results show a modeling effect. The different laboratory treatments of these sources are summarized in Table 1. Specific ments on the different laboratories All laboratories gave their laboratory temperature and humidity, but did not consider these values as sources of uncertainty, . the influence of temperature and humidity was neglected. This conclusion is reasonable for steel in the temperature range and humidity range in question [7]. Laboratory 1. The uncertainty due to the applied stress was determined taking load cell and dimensional uncertainties into account. The mathematical evaluation was made in accordance with the GUM. Specimen temperature was measured, but was implicitly neglected. The modeling problem was mentioned, but not con