Lateral Buckling Tests on Welded Continuous Beams

Twenty-one two-span continuous beams with nominally identical cross sections of welded I-250x100x6x8 mm are tested in seven groups of three, each group having different span length. These continuous beams are tested under a concentrated load on the midspan of one side span. The continuous test beams are on the simple and clamped supports at the both ends against in and out-of plane displacements with an intermediate support. The test results are compared directly with the buckling behavior of simple beams and also with the buckling results based on the effective length concept. The ultimate strengths of the present continuous beams are higher than those of simple beams and scatter between the elastic buckling strength curves of simple beams and of propped cantilever beams which are considered to have a nonloaded span with infinite rigidity. However, in the plot of (P\du/P\dy) vs (λ\N = P\dy/P\dE) the test results of continuous beams scatter on the lower part of the results of simple beams and the coefficients of variation are close to the values of simple beams.