This work is carried out as part of the study of the frame-rod structure with elements of thin-walled profiles. The results of a numerical study of a three-bolt connection of a thin-walled galvanized plate 1.5 mm thick with a plate of 3 mm thick on adjustable voltage bolts are presented. The calculation models are created by volume elements in Ansys software taking into account the strength properties of materials.

Keywords: galvanized thin-walled profiles, bolted joints, rod structures, thin-walled profiles, finite element method

The rapid development of infrastructure contributes to the development of building technologies and materials. Today, in addition to classic building materials, completely new technological composites - pultruded profiles - have appeared. These materials have a lot of advantages compared to classic materials, but this product also has a huge drawback - unstudied. To date, there are no widely accepted design standards or instructions available to practicing design engineers.As a consequence, now, most construction projects rely on manufacturers' design manuals, which are often incomplete and too cautious. The purpose of this article is to develop provisions for the calculation of structures of pultruded profiles

Keywords: pultruded profiles, stretched elements, calculation of stretched elements

Discusses the results of experimental rimentale-theoretical research of the building frame based on the tone-kostenich cold-formed profiles. In the course of research, the stress-strain state of the RA-we from thin-walled profiles was studied; the method of preliminary modeling of structural elements using FEM was developed; the design of the test bench and the composition of the test program of frames from thin-boned steel pro-files was developed; the comparison of the results of theoretical and experimental studies; the completion of numerical calculations of the con-struction nodes; the features of work under load and its compliance with the applied design scheme are studied.

Keywords: thin-Walled profile, construction Tests, finite element Method, Test bench

Discusses the research in the field of design of frame structures, the cross-trusses of thin-walled beams , preliminary finite element analysis of a thin-walled profile model with shelves of a bulk shaped element. Achievement in the analysis model, the corresponding test purposes.Determination of measurement error and results obtained in the calculation.Adjustment of the model.In this work, according to the results of the calculation, the mounting points of the strain gauge are taken close to the shaped element. Restrictions of displacements were introduced into the computational model for leveling the difference between the calculations and the experimental results. The results of the study profiles.

Keywords: method finite elements, thin-walled profile, core structures

This article presents the rationale for the selection of measuring instruments (strain gauges) for testing light steel thin-walled structures (LSTC) to determine the stress-strain state. Article discrebes in detail optimal sensor's installation locations, the required measures for correct value.

Keywords: thin-walled profile, test, frame, strain gauge, compression, tension, tension, bending, loss of stability

This article describes the definition of the approximating function of deflections of building structures using the method of least squares.

Keywords: the approximation function, the least squares method, the deflections of structures, prediction of deformations, the deformation of the structures

The material of the C-profiles in question, manufactured by the continuous rolling method, is galvanized steel up to 3.0 mm thick. Thin-walledness and the shape of the cross-section, causes a number of features of the profiles under load. The valid design norms in addition to the basic geometric parameters of the cross-sections used in calculating the longitudinal and bending forces (A is the cross-sectional area, Sx, Sv are the static moments of the section, Ix, Iv, Ixy are the axial and centrifugal moments of inertia) , Suggest the use of sector-specific characteristics. These characteristics are peculiar only to thin-walled rods and are determined on the basis of the notion of a sectorial area. The problem of determining the geometric characteristics of a thin-walled C-shaped profile is considered. The center of the bending is taken to be the point with respect to which the moment from the tangential forces arising during transverse bending or torsion in the cross section is zero. The position of the bending center does not depend on the forces acting on the rod, but depends only on the shape and dimensions of the cross-section of the thin-walled rod.

Keywords: steel structures, calculation of structures, thin-walled, profile, c-shaped, geometric characteristics, bending center

Study the main situation of Russian and foreign codes are considered, inadequate elaboration of the problem structural analysis of the progressive collapse, conclusions are draw on the basis of analysis of the available literature.

Keywords: Progressive collapse, steel constructions, codes, standarts, structural analysis of the progressive collapse, structural failure