CALCULATION METHOD FOR SINGLE-SPAN FRAMES, CONSIDERING THE JOINT OPERATION OF THE COLUMNS AND THE SHAPE OF THEIR DEFORMATIONS

Problem statement. A specific characteristic of modern skeleton calculation is the fact that only one column in a frame can be loaded with the maximum probable load. If one of the columns (at which the crane trolley with the load is located) is under maximum longitudinal force and bending moment, the opposite column of the same cross-section is loaded with significantly less effort. In the transverse direction, two columns of a single-span shop are connected by a crossbar into a frame system and the columns are not free to move. The development of significant plastic deformations in one of the columns does not cause loss of stability of the column, as it works as part of the frame. The opposing column takes up the growing load. Consideration of the joint operation of the columns as part of the frame will allow a more rational design according to current standards. The shape of the deformation of the short-curved frame is stimulated by the loads acting, usually not coinciding with the first proper form laid down in the standards. The load-bearing capacity depends on the ratio of the loads stimulating the different eigenforms and is always higher than that of the first curvature. The larger the higher forms are, the lower the deformability and the higher the load-bearing capacity of the system, and this has been experimentally verified. An approximate method for calculating the stability of compression-bent columns of steel frames with crane loads has been developed, which takes into account the joint operation of unequally loaded columns in the frame and the form of deformation under the action of active forces. The calculated column lengths determined for frames with crane loads according to the proposed method are smaller than the calculated lengths determined according to the standard method by 8−20 %.