DESIGNING A LATTICE ECCENTRICALLY COMPRESSED STEEL COLUMN USING COMPUTER SOFTWARE

Abstract

The article describes the theoretical substantiation of the methodology for using the MathCAD computer environment for the design of a lattice eccentrically compressed steel column, which consists of two branches. Such columns are part of the transverse frame of an industrial building. The crane branch is viewed as a normal I-beam with parallel flange edges. The outer branch is considered as a composite welded channel of three sheets. The branches are connected by a lattice of a triangular system located in two planes along the outer edges of the branches. It is assumed that the lattice through column operates as a hinged farm and longitudinal forces arise in its branches. The design of the column is carried out on the basis of ensuring the stability of both the column as a whole and its individual elements. The proposed algorithm for solving the problem in the MathCAD computer environment is divided into blocks that are designed to implement certain design stages. At the initial stage of the algorithm, the input of the initial data and the specification of the functions necessary for the calculation are provided. The subroutine for finding the number of a profile I-section crane branch is based on the principle of sequential viewing of the elements of the corresponding assortment. The viewing ends at the profile caliber at which the overall stability of the branch will be ensured. At the same time, the found caliber corresponds to the minimum cost of steel. The subroutine for determining the cross-section dimensions of the external compound branch is based on solving the system of equations for general and local stability using the MathCAD computer environment. Determination of the design dimensions of the column with the actual design longitudinal forces in the branches is performed by the method of successive approximations, since it is necessary to determine the actual position of the gravity center of the section. Successive approximation cycles are organized using the while operator. The stability of the branches in the plane of the transverse frame of the building is ensured by the appropriate software selection of the distance between the nodes of the lattice of the through column. The developed computer technique for determining the dimensions of the crosssection of the branches and braces of a lattice eccentrically compressed steel column opens up the opportunity to design such structures quickly and efficiently in accordance with the requirements of the current building codes.