Research On The Application Of Measurement Uncertainty In Experiment Of Concrete Beams

The defects and debates in the application of the classical error theory prevent measurement results from being used correctly. Under the promotion of several international organizations ,uncertainty of measurement has substituted for error and become an index of evaluating the reliability of measurement results. Uncertainty of measurement is a parameter associated with the result of a measurement that characterizes the dispersion of the values that could reasonably be attributed to the measurand, and describes the zone that measurement results locate in. It's on the base of error theory, but is greatly differential from error in signification, categories and evaluating methods.Although t he theory of measurement uncertainty has already established ,the research on its application in specific areas has to be deepened, and problems in the application has to be resolved. In this thesis, the application of measurement in experiment of concrete beams is studied, through evaluating the error of meter, SY-1 digital compression data log, deflection and the ultimate load-bearing capacity. The verification results are given through designing evaluation experiment, establishing mathematical models, analyzing resources of uncertainty, estimating distribution, evaluating Type A and Type B uncertainty by using statistical methods or non-statistical methods, combining them on the basis of the Law of propagation of uncertainty, and calculating the overall degrees of freedom.Through experiments and theoretical analysis, the related metrological concepts causing confusion are clarified;the mistakes in reality application are indicated, such as the classified uncertainty of measurement instruments should be given, the overall uncertainty of standard equipment should be given according to the classification of instruments being verified, the restriction condition for the methods of calculating coverage factors, some nonstandard expressions of uncertainty are corrected;the application of uncertainty of measurement in experiment of construction instead of the classical error theory,it can transfer uncertain error into certain quantitative data, provide us certain extent of last result of experiment of construction, and the last result, must be included between in one interval according to a special probability.