Grądzki, Ryszard2021-01-052021-01-051997Grądzki R., Influence of initial imperfections on the collapse behaviour of box-columns. W: VIII Sympozjum Stateczności Konstrukcji : referaty, Zakopane, 22-26 IX 1997, Królak M. (red.), Wydawca Politechnika Łódzka, Łódź 1997, s. 79-82.http://hdl.handle.net/11652/3149In this work the analysis of the post-buckling state in the elasto-plastic range of a box-colunm subjected to uniform compression in the elasto-plastic range is preseoted. The problem is investigated using Rayleigh-Ritz variational method. The stress-strains relations in the plastic range are determined on the basis of the flow theory of plasticity. The proposed method is a combination of analytical and numerical solutions. Different materiał stress-strain curves and initial imperfections such: out-of-flatness and residual stresses are taken into account. The load-shortening curves for column of different geometrical parameters and material properties are shown in diagrams.enbox columnthe flow theory of plasticitybucklinganalysis of the post-buckling stateprzepływowa teoria plastycznościkolumna pudełkowawyboczenieanaliza stanu po wyboczeniuarticle