外文翻译--关于北欧的疲劳实验室的比较—测量结果不确定值的反映(编辑修改稿)

外文翻译--关于北欧的疲劳实验室的比较—测量结果不确定值的反映(编辑修改稿)内容摘要：

rol system deviations are considered, but not included in the uncertainty evaluation. The failure criterion is mentioned and regarded as negligible, and corrosion is mentioned as a possible source of uncertainty. Laboratory 5. Uncertainties in the load cell and the load control were considered, and the laboratory stated in the report that the evaluation of the load uncertainty was performed according to the CIPM method. Laboratory 6. No report was provided, but only experimental results and a Whaler curve estimate. No laboratory reported the uncertainty in the estimated material properties, the Whaler parameters, but at most the uncertainty in the applied stress. The overall picture of the uncertainty considerations is that only uncertainty sources that are possible to estimate from calibration reports were taken into account in the final evaluation. Fig. 1 All experimental results and estimated Whole curves from the different laboratories Number of cycles to failure One important source that several laboratories mentioned is the bending stresses induced by misalignment in the testing machine, incorrectly mounted test specimens or ―incorrect‖ specimens. The amount of bending stress was also estimated in some cases, but its influence on the uncertainty in the final Whole curve was not investigated. The results from this experimental investigation show that there are different ways of determining the Whole curve from the experimental result. One problem is the surviving specimens, the runout results. Four laboratories used only the failed specimens‘ results for the curvefit, one laboratory neglected all results at the lowest level, and one laboratory included the runouts in the estimation. Another problem is the mathematical procedure for estimating the curve. Common practice, and the remendation in the ASTM standard, is that the curve should be estimated by minimizing the squared errors in log life, . the statistical model is log log logN a b S   , (1) Where e is a random error, assumed to have constant variance, and where log stands for the logarithm with base 10. E can be interpreted as the bination of at least two types of errors: namely (1) a random error due to the scatter in the material properties, and (2) a measurement error due to uncertainties in the measurement procedures. Fig. 2 All experimental results and estimated Whole curves using the mon procedure Number of cycles to failure Table 1 Sources of uncertainty and laboratory treatment C The laboratory report considers the source explicitly or implicitly, N the laboratory report neglects the source, A the laboratory report takes the source into account in the uncertainty of measurement calculation Where e is a random error, assumed to have constant variance, and where log stands for the logarithm with base 10. E can be interpreted as the bination of at least two types of errors: namely (1) a random error due to the scatter in the material properties, and (2) a measurement error due to uncertainties in the measurement procedures. Stress was minimized, which led to a model discrepancy as discussed in the following. Discussion Experimental results Most laboratories performed estimations of the Whaler curve parameters. Visual parison of their estimated curves suggests differences, and a statistical test verified the conclusion that there is a statistically significant laboratory effect. A closer study of each participant‘s procedure for determining the Whaler curve shows that the differences seem to be caused by different modeling of the curve. Since the test was intended to simulate a customer ordered test, some specific problems occurred. First, the number of test specimens is limited and therefore one should be careful when drawing conclusions from the results, since the scatter is considerable in fatigue and the number of specimens are limited. Another problem that occurred was that, since runouts were wanted, two different failure criteria (failure mechanisms) were used to halt the test: fracture of the test specimen or 6510 cycles. In the latter case, the use of the equation log logA B N  may cause problems, see later. The investigator then looked at whether any laboratory differences remained after excluding the model interpretation effects. This was acplished in two ways: Namely, firstly by direct parison of the experimental fatigue lives obtained, and secondly by using the same estimating procedure on all data sets. This therefore tested whether any laboratory differences remained or not. The。