ОПРЕДЕЛЕНИЕ РАСЧЁТНОЙ ДЛИНЫ ПОЯСА ФЕРМЫ ПРИ УПРУГОМ ПОДКРЕПЛЕНИИ ИЗ ПЛОСКОСТИ.

Abstract

An algorithm for determining the effective length for a compressed chord of a U-shaped truss using numerical methods is presented, and the results are compared with analytical calculations [6]. The classic bracing solution for bracing compressed truss chords of any spans involves the installation of bracing blocks that prevent the truss nodes from moving out of plane. In engineering practice, there are solutions in which there is no constructive possibility of installing tie blocks along compressed chords of trusses. An example is the U-shaped truss of overhead open pedestrian bridges, in which the running surface is located at the level of the lower chords, and the upper chords of the trusses are located at the level of the handrails of the fence. The design solution of a U-shaped truss is presented in Figure 1. The standards [1] provide formulas for determining the design length of a truss chord (continuous rod) with different compressive forces in sections, but there is no engineering method for calculating the design length of a truss chord depending on elastic lateral torsional. Due to the fact that domestic standards [1], [2] and [4] establish clear mathematical laws for calculating the design lengths of compressed rods, solving the posed engineering problem is possible, for example, using numerical methods.