Bending Moments due to Elastic Buckling Mode Applied as Uniform Global and Local Initial Imperfection of Frames

The verification of the stability of frames or their parts carried out considering imperfections and second order effects accounted for by global analysis. The shape of the elastic critical buckling mode r/CT (x) of the structure is applied as a unique global and local initial (“ugli”) imperfection t]Ugli(x) =t]init(x) with amplitude t]Q UgUm proposed by Professor Chladny. Detailed description of the procedure of iterative calculation based on Chladny's method but different from it may be found in [1], . The graphical interpretation of the results proposed by the authors and numerical example for two-hinged portal frame with uniform cross-sections and uniform axial compression forces based on [1] are presented.