Structural safety of rolled and welded beams subjected to lateral‐torsional buckling

The expediency of using probability‐based approaches in the analysis of beams subjected to lateral‐torsional buckling is discussed. The values of buckling resistance moments and their uncertainties for rolled and equivalent welded I sections as particular members of the designed structures are analyzed. The safety margins of buckling steel sections exposed to permanent and variable vertical loads are modeled. The survival probability and reliability index of sections exposed to lateral‐torsional buckling are considered. The prediction of probability‐based safety of rolled and welded beams in buildings and civil engineering works are provided and illustrated by numerical examples. Santrauka Aptariamas tikslingumas naudoti tikimybinius metodus skaičiuojant šoniniu sukimu klupdomas sijas. Analizuojamos val‐cuotuju ir suvirintuju I profiliuočiu, kaip ypačiuju elementu, klupdomuju atspariu momentu vertes ir ju neapibrežtys. Mo‐deliuojama nuolatine ir laikinaja vertikalia apkrova klupdomu plieniniu profiliuočiu ribine sauga. Nagrinejama šoniniu sukimu klupdomu profiliuočiu išlikties tikimybe ir patikimumo indeksas. Pateiktas ir skaitiniu pavyzdžiu iliustruotas pas‐tatu ir inžineriniu statiniu valcuotuju ir suvirintuju siju tikimybines saugos prognozavimas. First Published Online: 24 Jun 2011 Reikšminiai žodžiai: plieniniai profiliuočiai, klupdymas šoniniu sukimu, ribine sauga, išlikties tikimybe, suvirintosios sijo