ASSESSMENT OF MODEL UNCERTAINTY IN SHEAR RESISTANCE PROVIDED BY EN 1993-1-5 AND SNIP II-23
The paper is focused on the model uncertainty related to the shear resistance of steel elements with transverse stiffeners on the basis of available test results. The paper shows the general characteristics of resistance models for shear which are used in the regulatory documents EN 1993-1-5 and SNIP II-23. Their areas of application are described. The procedure for selecting the experimental values of shear resistance is described, as well. Comparison of experimental and theoretical values of the shear resistance is performed. Statistical characteristics of the model uncertainty of the shear resistance of steel elements having transverse stiffeners are obtained. Variation of the model uncertainty using basic variables is analyzed, and significant variables are identified for the models specified in SNIP II-23. In the paper, probabilistic description of model uncertainties is analyzed. The proposed probabilistic description of the model uncertainty consists of the lognormal or normal distribution having the coefficient of variation of 0.16 and the mean value of 1.18. The author believes that further research into the models of shear resistance specified in SNiP II-23 is required with a view to their improvement. The database of experimental findings in the area of shear resistance is compiled.