Steel structures: numerical analysis of fire proofing

Abstract

Introduction. A set of calculations validating the conditions of limit states is to accompany the design of buildings and structures. Calculations of standard and non-standard combinations of loads and impacts are performed. Special loads include temperature effects from explosions and fires. Such effects greatly reduce the bearing capacity of metal structures. To protect metal structures from temperature effects, optimally selected fire proofing materials (varnishes, paints, various types of cladding) should be used. Numerical calculation methods allow analyzing the performance of building structures, exposed to temperature effects, and help select the necessary characteristics and thicknesses of fire proofing materials. Materials and methods. A metal hinged beam is used to analyze the influence of fire proofing, or lining made of fire-resistant gypsum sheets (FRGSh). Analytical and numerical methods of calculations were used to obtain the fire resistance limit of beams with cladding. The analytical method is based on the laboratory studies of fire resistance, as a result of which nomograms were obtained. The numerical method is implemented by Lira 10.12 software package. Results. Analytical and numerical methods were used to identify the fire-resistance limits for a beam that had FRGSh cladding. Temperature field mosaics in the elements along the thickness of the structure, as well as graphs of temperature changes and temperature fields in time were obtained using the numerical method. The obtained results showed good convergence. Conclusions. The use of numerical methods makes it possible to quickly and optimally select the required thickness of fire proofing for a steel structure. Calculation results are highly dependent on the characteristics of the materials in question, as well as the heat transfer environment.