EXPERIMENTAL AND THEORETICAL TESTING OF THE EFFECTIVENESS OF CONSTRUCTIVE MEASURES TO PREVENT THE PROGRESSIVE COLLAPSE OF THE SPECIAL TYPE METAL SHELLS

Abstract

The article considers frameless structures in the form of special type metal shells. The main structural element of these special shells is arched thin-walled cold-deformed profiles. The construction of structural elements takes place directly at the construction site. The main anomalies of the exploitation of the specified structures are considered. The main of these anomalies of exploitation is a certain number of accidents and collapses, which, after detailed analysis, can be classified as progressive or “avalanche-like” collapse. The computational algorithms for estimating the stress-strain state and preventing measures the onset of a progressive collapse of special type metal shells are considered. As the preventing measure was described constructive modernization of the original junction of arched structural elements. The aim of the research was to assess the impact of the proposed constructive modernization on the deformation properties of special type metal shell during a two-stage full-scale experiment. The block under research was close to a square, in the plan, cylindrical composite coating shell. Block dimensions: span between side elements 22m., Block length 15.6m., Lifting arm 8.37m., Radius of the cylindrical shell 11.585m. The thickness of the steel element was 1.2 mm.A comparative finite-element analysis of the stress-strain state of the original models of special type metal shell, models of the discrete-continuum ribbed shell (with the implementation of constructive modernization of the joint) was also carried out. The results of the analysis are presented in the form of comparative graphs of displacements of tracked points from loading. The results obtained testify to the effectiveness of the proposed constructive modernization of metal shells of a special type, as measures preventing the onset of progressive collapse of these shell systems.