Устойчивость ветвей решетчатых элементов стальных конструкций

Abstract

There has been obtained a solution of the problem of the general stability of the lattice rod, taking into account the stability of the branch between the lattice nodes (local stability) in an analytical form, which is convenient in practical application. It allows taking into account the impact of defects and damages, as well as the misalignment of the lattice nodes on the overall stability of the through rod. It is shown, that with conditional flexibility of the branch, the decrease in overall stability may be significant. Two-branched rod elements isolated from the design according to the calculated length from the lattice plane are almost always loaded in the lattice plane with different values of longitudinal force and bending moment at the ends.Consequently, the longitudinal forces in the branches most loaded from the lattice plane will always be variable. The use of the actual loading scheme in solving the stability problem allows revealing very significant reserves of load-bearing capacity. The solution is obtained by means of the inverse numerical-analytical method, which allows performing the calculation in almost a few seconds. The speed of the solution depends on the number of iterations necessary to find solutions, the mechanism used to «hold» the values of relatively small (inherent in the branches) eccentricities of the longitudinal force constant.