Studies on buckling lengths of chords for out-of-plane instability

In the article a more precise models of assessing the out-of-plane loss of stability of chords of oneway trusses have been proposed. The more exact values of the out-of-plane buckling length coefficients of chords have been determined. On this basic the more estimation assesses of chord's resistance is possible by using the indirect method of analysis and designing of steel bar structures. The model of compression chord as a straight member isolated from the one-way truss associated with the space model of lateral buckling of the truss have been analysed. The problem has been studied parametrically by changing the number of web panels. For the tested models, the comparative analyses of the out-of-plane buckling length coefficients have been carried out referring to the guidelines of chosen design codes. It has been confirmed that the chord's out-of-plane buckling length might be smaller or larger than the distance between the points of truss' bracing.