【正文】 這個原因可能是最近幾年關于測量的不確定性值的討論已經(jīng)集中在用什么方程和計算上，例如，測量的不確定性值應該在報告中直接報告，或者只有當顧客要求時才報告，或者代替真正的技術(shù)論題。這很令人吃驚，因為歐洲權(quán)威機構(gòu)已經(jīng)引用它好幾年了。在得出報告疲勞壽命方法的任何意見之前，具體定義實驗模型的測量報告是很重要的。另一個問題是，用兩種不同的方法做實驗得出兩種不同的結(jié)論。 不同實驗室的所有實驗結(jié)果和維勒圖表結(jié)果如圖 1所示： 圖 1 不同實驗室的所有實驗結(jié)果和維勒圖 實驗結(jié)果表明，決定實驗結(jié)果的維勒圖表有不同的畫法，其中的問題就是模型的不確定性值和最終結(jié)果。評估的方法與 GUM 方法無關，但是被證明有絕對的錯誤。 不同實驗室的具體評論 所有的實驗室都設定了室內(nèi)溫度和濕度，但是他們沒有把它們看成是誤差的因素。它顯示了各實驗室之間的顯著的差別。 實驗程序 ： 參與者收到了沒有數(shù)據(jù)的材料模型，及其如何進行測量和如何報告結(jié)果的信息。目前的方法集中在一種更加科學的方法上。 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 considered as an uncertainty source. Laboratory 2. The report contains no uncertainty evaluation. The uncertainties in the load cell and the micrometer are considered, but neglected with reference to the large material scatter. Specimen temperature was measured. Modeling problems are mentioned by a ment regarding the choice of load levels. Laboratory 3. The report contains no uncertainty evaluation. However, the accuracy of the machine is given and the load was controlled during the tests to be within specified limits. The bending stresses were measured on one specimen, but their influence on the fatigue result was not taken into consideration. Laboratory 4. The uncertainties in the load cell and the dimensional measurements are considered in an evaluation of stress uncertainty. The method for the evaluation is not in accordance with the GUM method, but was performed by adding absolute errors. The bending stress influence and the control system deviations are considered, but not included in the uncertainty evaluation. The failure criterion is mentioned and regarded as negligibl