Wpływ tarcia w przegubach na przebieg wyboczenia pręta ściskanego

The paper presents the problem of the influence of friction occurring in the hinges on the buckling process of a simply supported column with a small initial curvature. It has been found, that the initial clamping of the ends of the bar is possible for the type of the hinge actually used in the experiments. Thus the buckling process runs in two stages. The first stage (bar with fixed ends) terminates, when the clamping moments exceed the friction moments. In the second stage the same bar is analyzed with two hinges at the ends, but it is additionally loaded with the friction moments at these hinges. At the end of the first period, the column may be stable even under the loading, exceeding the critical Euler force at the simply supported rod.