Моделювання напружено-деформованого стану просторової галереї хімічного виробництва, що зазнала корозійних пошкоджень, для раціонального підсилення

Abstract

The article deals with the solution of an important scientific and practical problem of modeling the stressstrain state of building structures of an industrial metal gallery, which is part of the general technological line of production and overloading of mineral fertilizers. The building structures of the research object – the transport gallery – were built on the territory of JSC "OPP" in the Yuzhne town, Odesa region. Metal constructions of the gallery support the constructions of belt conveyors (transporters) and constructions of protective cladding. Conveyors are located inside the gallery and are designed for overloading in bulk or in urea bags. The article contains a detailed technical description of the construction of the gallery, which is a spatial rod metal structure consisting of four flat frames (roof, walls and bottom) which rests on a system of hinged movable and fixed supports. The bottom level sheathed by shell with rhombic corrugation, the cladding of the metal frame on the other three sides is decided in the form of a corrugated board. The article has given the typical defects and damage to the building, discovered during the inspection. Their systemic nature has been emphasized. The article determines the localization of defects and the degree of wear and tear of the main building structures of the galleries on the basis of instrumental studies, the technical condition. During the examination it has been found that, as a result of the destructive effect of moist sea air with microparticles of mineral fertilizers suspended in it, individual structures of the gallery have suffered significant losses from corrosion and are in a state of emergency or unsuitable for normal operation. Detailed finite-element models of the stress-strain state of the gallery under the action of a complex of static and dynamic climatic and technological influences were developed on the basis of the measurements and survey results. The scientific analysis of the modeling results proved that the gallery, as a whole, and individual, most worn elements cannot perceive the design effects on the structure, taking into account the normative reliability coefficients. It has been emphasized that due to the lack of alternative methods of overloading of urea, the gallery cannot be completely decommissioned during the reinforcement period. When solving the problem, the following methods have been used: visual inspection, measurements of structures, determination of corrosion wear of structures by ultrasonic method, finite-element modeling of the stress-strain state using the CAD toolkit - SCAD Soft, verification calculations of the metal frame components of the gallery. The rational method of strengthening the metal structures of the gallery has been offered, based on the results of the survey, modeling and strength designs, which consists in temporarily reducing the loads on the conveyor system (up to 50% of the design), unloading the main defective joints of the belts, safe installation and inclusion in the work of additional reinforcement structures without dismantling the existing ones damaged by corrosion. The specified results can be extended to most similar long-span metal technological gallery type structures due to their structural and technological versatility