【正文】 中文 4060字 出處： Accreditation and quality assurance, 2020, 10(5): 208213 附錄 附錄 1 英文原文 Reflections regarding uncertainty of measurement, on the results of a Nordic fatigue test interlaboratory parison Magnus Holmgren, Thomas Svensson, Erland Johnson, Klas Johansson Abstract This paper presents the experiences of calculation and reporting uncertainty of measurement in fatigue testing. Six Nordic laboratories performed fatigue tests on steel specimens. The laboratories also reported their results concerning uncertainty of measurement and how they calculated it. The results show large differences in the way the uncertainties of measurement were calculated and reported. No laboratory included the most significant uncertainty source, bending stress (due to misalignment of the testing machine, ―incorrect‖ specimens and/or incorrectly mounted specimens), when calculating the uncertainty of measurement. Several laboratories did not calculate the uncertainty of measurement in accordance with the Guide to the Expression of Uncertainty in Measurement (GUM) [1]. Keyword： Uncertainty of measurement, Calculation, Report, Fatigue test, Laboratory interparison Definitions ： R Stress ratio Fmin/Fmax F Force (nektons) A and B Fatigue strength parameters s and S Stress (megapascals) N Number of cycles. Introduction The correct or best method of calculating and reporting uncertainty of measurement in testing has been the subject of discussion for many years. The issue became even more relevant in connection with the introduction of ISO standards, . ISO17025 [2]. The discussion, as well as implementation of the uncertainty of measurement concept, has often been concentrated on which equation to use or on administrative handling of the issue. There has been less interest in the technical problem and how to handle uncertainty of measurement in the actual experimental situation, and how to learn from the uncertainty of measurement calculation when improving the experimental technique. One reason for this may be that the accreditation bodies have concentrated on the very existence of uncertainty of measurement calculations for an accredited test method, instead of on whether the calculations are performed in a sound technical way. The present investigation emphasizes the need for a more technical focus. One testing area where it is difficult to do uncertainty of measurement calculations is fatigue testing. However, there is guidance on how to perform such calculations, . in Refs. [3, 4]. To investigate how uncertainty of measurement calculations are performed for fati gue tests in real life, UTMIS (the Swedish fatigue work) started an interlaboratory parison where one of the most essential parts was to calculate and report the uncertainty of measurement of a typical fatigue test that could have been ordered by a customer of the participating laboratories. For cost reasons, customers often ask for a limited number of test specimens but, at the same time, they request a lot of information about a large portion of the possible stresslife area [from few cycles (high stresses) to millions of cycles (low stresses) and even runouts]. The way the calculation was made should also be reported. The oute concerning the uncertainty of measurement from the project is reported in this article. Participants Six Nordic laboratories participated in the interlaboratory parison: one industrial laboratory, two research institutes, two university laboratories and one laboratory in a consultancy pany. Two of the laboratories are accredited for fatigue testing, and a third laboratory is accredited for other tests. Each participant was randomly assigned a number between 1 and 6, and this notification will be used in the rest of this paper. Experimental procedure The participants received information about the test specimens (without material data), together with instructions on the way to perform the test and how to report the results. The instructions were that tests should be performed as constant load amplitude tests, with R= at three different stress levels, 460, 430 and 400 Map, with four specimens at each stress level, at a test frequency between 10 and 30 Hz, with a runout limit at 6510? cycles and in a normal laboratory climate ( 020 3C? and 50 15%? relative humidity). This was considered as a typical customer ordered test. The test results were to be used to calculate estimates of the two fatigue strength parameters, A and B, according to linear regression of the logs and long variables, logA B N? ?? . Th