engleski

Structural reliability of steel beams and plate girders

The beam design requirements for limit state lateral torsion buckling are analyzed and criteria for two codes (AISC and ECCS) are compared. As the differences in the design requirements are substantial, the comparison of the achieved reliability indices is made in order to find out the four example is done concerning with the various observation data of snow loads on four locations in Croatia. The statistical parameters of the experimental results are evaluated and FOSM method is used for the procedure of the calibration. As the results varies with the applied snow loads and the slenderness ratios, for two examined models of the designed rolled beams, which are compared, it is necessary to achieve target values of reliability by correction of the model and resistance factors. The parameters of imperfection were derived from the equation for buckling of compression members, by means of nonlinear regression analysis using results from experimental research. New values α for parameters of imperfection have been obtained so that α amounts to 0.077 for the mean value, while α =0.247 for the 95% fractile value. Out of the total of 318 rolled beams tested, 17 samples are below the proposed model by α =0.247.

reliability analysis; experimental results; statistical parameters; rolled beams; plate girders; model and resistance factor

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