Reserves of the bearing capacity of metal columns as part of a single-span frame with crane loads

Abstract

The search for reserves of bearing capacity and improvement of the calculation of compressed-flexural metal columns is an urgent task. This makes it possible to more fully take into account the actual operation of structures and metal savings. An analysis of these and other issues is given in this paper on the basis of theoretical and experimental studies of life-size compressed-curved columns as part of a single-story and single-span industrial building with overhead cranes. The purpose of this work was to search for reserves of the bearing capacity of compressed-bent columns as part of the diameter of one-story single-span buildings with overhead cranes. As a result of the theoretical studies carried out, a method for calculating the stability of compression-bending columns as part of a cross section with crane loads has been developed. The technique takes into account the compatibility of the work of unevenly loaded columns in the frame and the shape of the deformation of the columns under the action of an active load. The estimated length calculated for frames with crane loads according to the proposed method is less than the estimated lengths according to current standards by 8-20%. To implement the tasks set in the experiment, a stand was developed and manufactured that allows testing the column as part of the frame and applying all types of vertical and horizontal loads to it. Experimental studies of full-scale compression-bending columns as part of a frame with the application of all loads that act on them (permanent, wind and crane) at different stages of the load, up to the exhaustion of the bearing capacity, made it possible to investigate the actual stress-strain state of the columns and their movement, bending of column base plates, development of current deformations in web flanges, local buckling of flanges and webs, general buckling of columns in the frame. For reconstructed industrial enterprises, a method for determining the reserves of bearing capacity for vertical load based on multiparameter loading of the diameter is proposed.