Literature review on beam buckling lengths and methods to calculate the real buckling length

Abstract

In this literature study the buckling of frames is investigated. Two frames are considered, where both consists of two columns and a girder. The first step was looking at the behavior of a single column under an compressive load. This results in so called effective lengths for different sets of boundary conditions on the column. Because in a frame the multiple columns and girders work together, the buckling mode also depends on the frame itself and the neighboring beams. There are two types of frames according to their buckling mode, a sway and a non sway frame. For determining the effective buckling lengths Eurocode 3 is studied for general rules for frames and calculation methods for effective lengths. Also the method from the AISC standard is described shortly. After that, it is investigated what methods the FEM programs use. Beside these methods, another method has been found and will be demonstrated on both situations. In the last chapter the results are summarized and a final conclusion and recommendation are made.