A mechanically consistent approach for stability verification of timber beams in compression and bending around the strong axis - part 2: experimental tests and numerical simulation

Slender timber beams in bending can be designed using different methods in view of out-of-plane stability. Lateral torsional buckling may be verified either using the so called equivalent member method or by means of 2nd order calculations, considering equivalent imperfections. Applying current codes, however, determining the lateral torsional buckling resistance using either of these both methods, leads to different results. In this paper, the background of both verifications is investigated in deep. Moreover, as an alternative approach, a non-linear calculation with an imperfection shape in affinity to the critical shape was presented in part 1 of this paper. By scaling the curvature, the same results as by the equivalent member method can be achieved. It was shown that plasticity effects can be considered as well. In this part 2, results of lateral torsional buckling tests on glued laminated timber beams are presented, with nearly ideal boundary conditions and load direction remaining vertical through-out the test. Based on these test first tentative values can be obtained for the imperfection compatible with the alternative lateral torsional buckling approach presented.