LATERAL-TORSIONAL BUCKLING OF I-SECTION BEAMS WITH INITIAL RANDOM IMPERFECTIONS

The paper deals with a statistical analysis of load carrying capacity of a simply supported straight I-beam with equal end moment with cross-section IPE 220, solved by geometrically nonlinear solution influenced by lateral-torsional buckling. The beam was modelled applying the programme ANSYS on behalf of the element BEAM188. Imperfections were considered to be random quantities. The initial curvature and the axis rotation are considered to have the shape of one half-wave of the sine function. The correlation between the amplitudes of initial curvature and initial rotation of the axis is considered as the parameter of solution within the interval from -1 to 1. The influence of this correlation on the change of mean value and standard deviation of random load carrying capacity is studied, the other imperfections being considered to be random quantities resulting from experiments. Realizations of initial imperfections are simulated applying the Latin Hypercube Sampling method. The conclusion presents a discussion of need of paying attention to initial torsion of the axis, when creating stochastic computational models.