Reliability Analysis of the Lateral Torsional Buckling Resistance and the Ultimate Limit State of Steel Beams With Random Imperfections

Abstract

The paper deals with the analysis of reliability of a hot-rolled steel IPE-beam designed according to Eurocodes. A beam at its ultimate limit state is considered. The load acting on the beam consists of permanent and long-term single variation actions. The beam is loaded with end bending moments about the major principal axis. The beam is susceptible to lateral torsional buckling between the end supports. Reliability of the beam is assessed using probabilistic analysis based on the Monte Carlo method. Failure probability is a function of the random variability of the loadcarrying capacity and the random variability of load effects. The variability of the load-carrying capacity is influenced by the variability of initial imperfections. Imperfections are considered according to experimental research. Numerical studies showed that the failure probability is significantly misaligned. High values of failure probability were obtained for slender beams, for beams loaded only by permanent load action, and for beams loaded only by long-term single variation load. In further studies the values of partial safety factors of load and resistance were calibrated so that the failure probability had a target value of 7.2E-5. Relatively high values of partial safety factors were obtained especially for beams with high slenderness.

Quantile-Oriented Global Sensitivity Analysis of Design Resistance

“…The calculation of R d is based on the semi-probabilistic approach (Freudenthal, 1956) of standard EN 1990standard EN :2002standard EN (2003, which falls into the category of FORM methods (Sedlacek & Müller, 2006). R d given as 0.1 percentile corresponds to design reliability with target reliability index of β d = 3.8 (failure probability P f = 7.2E-5) provided that we consider the ultimate limit state for common design situations within the reference period of 50 years, see Table C2 in EN 1990EN :2002EN (2003 and/or Kala (2015). Standard EN 1990:2002(2003 enables the determination of design values not only from a Gauss pdf, but also from the two-parameter lognormal or Gumbel pdf, which is often assumed to reflect the effects of the random load.…”

Probabilistic Verification of Structural Stability Design Procedures

“…For design reliability index β d = 3.8, the design load-carrying capacity can be computed as 0.1percentile [14]. Reliability index β has a target value of 3.8 provided that we consider the ultimate limit state for common design situations within the reference period of 50 years [29]. The design reliability index β d = 3.8 can be used for medium consequences of loss of human life, economic, social or environmental consequences.…”

Diagnostics of Corrosion on a Real Bridge Structure

“…To fulfill the main objective of the project, it is needed to collect data about codes, standards, and provisions concerning the inspections, evaluation, environment loads and conditions [2,3], degradation processes [4][5][6], reliability [7][8][9], fatigue [10,11], monitoring, maintenance, and diagnostic [12][13][14] of road bridges in all countries included in the project. The Department of Structures and Bridges, University of Zilina, was included into the project to represent Slovakia.…”