Faculty of Civil Engineering
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Item type:Publication, POST EARTHQUAKE FIRE RESISTANCE OF RC FRAME(2017-01); ; ; Stevanovic, BoskoFire following an earthquake is an important factor causing damage to buildings and life-line structures. Therefore, besides satisfying structural design requirements for normal loads, such as dead and live loads, including the seismic hazard, buildings should also be designed to withstand the fire following earthquake for a certain minimum duration as required for a desired level of performance. Calculating structural response to fire after earthquake is a few step process: modeling the structure including nonlinear analysis options; choice for earthquake analysis scenario; seismic nonlinear analysis: pushover or dynamic time history; fire hazards analysis to identify all possible fire scenarios; thermal analysis to calculate temperature history in each member; structural analysis to determine forces, stresses and deformations to estimate whether local or global collapse would occur during any of the fire hazard scenarios. To evaluate the seismic damage in a structure, first, the seismic hazard level is determined from the seismic hazard spectrum for the given site, followed by the selection of appropriate ground motion records and structural analysis. The seismic excitation induces damage and lateral deformation provoking additional stresses in the frame due to the moment caused by the P-D effect. Structural members and joints are also weakened by the cyclic inelastic deformation, causing stiffness and strength degradation. Once the earthquake-induced damage in the structure is determined, the damaged structure is subjected to a post earthquake fire (PEF) scenario, which involves fire hazard analysis to determine the time history of fire growth and spread and stress and collapse analysis of the structure but also to analyze no-collapse conditions and cooling after fire. The behavior of a particular reinforced concrete structure that was fire exposed after seismic action is presented in this paper. The seismic response of the structure is evaluated using a pushover analysis, while the displacement demand under the corresponding seismic event is determined using the recommendations implemented in Eurocode 8. The earthquake-induced damage in the structure is determined and, as next step, the structure is exposed to Standard fire ISO 834. For that purpose the program FIRE, based on FEM, is used. The program FIRE carries out the nonlinear transient heat flow analysis and nonlinear stress-strain response associated with fire. The solution technique used in FIRE is a finite element method coupled with time step integration. The computer modulus FIRE-T solves the governing differential equation of heat transfer in conduction. The response of a reinforced concrete elements and plane frame structures exposed to fire is predicted by modulus FIRE-S. This modulus accounts for: dimensional changes caused by temperature differences, changes in mechanical properties of materials with changes in temperature, degradation of sections by cracking and/or crushing and acceleration of shrinkage and creep with an increase of temperature. Pushover analysis, representing dynamic effects of an earthquake via static nonlinear procedure, is incorporated in the program as an option that precedes the postearthquake fire analysis. - Some of the metrics are blocked by yourconsent settings
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Item type:Publication, Prognostic modelling of fire resistance of RC columns using the concept of ANN(2017); ; The application of artificial neural networks, as an unconventional and innovative method for solving complex civil engineering problems, is very important for modernization of the construction design processes. Many published studies show that neural-based approach can be successfully used in different engineering fields. Neural networks are being used for creating prognostic models mainly in those cases where some prior (numerical or experimental) analyses were already made. This paper presents a neural network prognostic model used for determination of fire resistance of reinforced concrete columns exposed to standard fire from all four sides is presented in the paper. The proposed model relies on the concept of artificial neural networks, in which numerical analysis results are used as input parameters. A brief description of the modelling process is given, and an appropriate example of the neural network prognostic model is presented. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Bond stress distribution along CFRP strengthened RC beam(Drustvo gradjevinskih konstruktera Srbija, 2018-09); ; ; knezevic, MilosA large number of existing RC structures exhibit non adequate performance in terms of diminished bearing capacity and there is a need of post strengthening during their service life. The aim of the presented work was to numerically assess the influence of the presence of discontinuous zone upon overall response of the CFRP strengthened RC beam. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Influence of the type of reinforcement on the behavior of FRP materials at indoor and elevated temperatures(Fakultet tehnickih nauka, Novi Sad, 2015-11); ; Increasing interest about composite materials and their use in the field of civil engineering offers possibility for development of new innovative materials, which will be used as constructive elements. the concept of the composite materials itself, offers possibility of effective exploitation of mechanical characteristics of the separate components till their limit, even in the design process. Mechanical characteristics of each composite material depend on its components. In this paper experiments of different series composite materials differed by the type of used reinforcement are presented. Experimentally observed mechanical characteristics of different types of composite materials are discussed in dependence on used reinforcement at indoor and elevated temperature. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, The use of Fuzzy Logic for management of civil engineering projects(University of Montenegro, Faculty of Civil Engineering, 2016-03); ; characterized with significant risk, uncertainty and lack of precision, all of which are a direct result of the changing nature of civil engineering. Due to this, the development of deterministic mathematical models for solving various problems within the area of civil engineering represents a difficult and pretty expensive task. As a result, an idea emerged for using innovative methods and techniques through which in a simpler manner, but still successfully, the solving of problems related to the management of civil engineering projects would be enabled. Among these methods, the use of fuzzy logic particularly stands out. This paper presents the theoretical base of fuzzy logic and its application in the management of civil engineering projects. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, COMPOSITE MATERIALS AND SANDWICH PANELS WITH COMPOSITE FACE SHEETS WITH POLYESTER AND EPOXY MATRIX(University of Zagreb, Faculty of Civil Engineering, Zagreb, Croatia, 2017, 2017-04); ; This paper presents the experiment test for the tensile properties of two series of composite materials and two series sandwich panels with composite face sheets, which differed according to the type of matrix. The ultimate tensile strength and the initial module of the elasticity of the composite materials were experimentally determined. Sandwich panels in the experimental tests were subjected on three points bending by linear load in the middle of their span. The analysis was performed in order to evaluate the influence of the matrix type on the ultimate mechanical characteristics of the sandwich panels. Influence of the matrix type used in the composite face sheets was evaluated by analysis of F ‒ δ behavior of series of sandwich panels, as well as by analysis of F ‒ σ behavior of the composite face sheets. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, INFLUENCE OF THE COMPRESSIVE STRENGTH OF THE CONCRETE ON CFRP STRENGTHENED RC BEAM(Drustvo gradjevinskih konstruktera Srbije, 2016-09); ; A large number of existing RC structures, whether they have been built of concrete with usual compressive strength or of concrete with high compressive properties, exhibit non adequate performance in terms of diminished bearing capacity and there is a need of post strengthening during their service life. This paper presents numerical analysis of the influence of the compressive strength of the concrete on the performance of the CFRP strengthened RC beam. Analysis is performed for two characteristic cases: when the bond between concrete and external reinforcement is continuous along the length of the beam and when the bond is improper executed creating discontinuity zone between RC and CFRP plate. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Influence of the compressive strength of the concrete of CFRP strengthened RC beam(Drustvo gradjevinskih konstruktera Srbije, 2016-09); ; A large number of existing RC structures, whether they have been built of concrete with usual compressive strength or of concrete with high compressive properties, exibit non adequate performance in terms of diminished bearing capacity and there is a need of post strengthening during their service life. This paper presents numerical analysis of the influence of the compressive strength of the concrete on the performance of the CFRP strengthened RC beam. Analysis is performed for two characteristic cases: when the bond between concrete and external reinforcement is continuous along the lenght of the beam and when the bond is improper executed creating discontinuity zone between RC and CFRP plate. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Fire resistance of one-way simply supported RC slabs(Drustvo gradjevinskih konstruktera Srbije, 2017-09); ; This paper presents the numerically achieved results for the fire resistance of one-way simply supported RC slabs. The effects of: concrete cover thickness, reinforcement ratio, slab span and thickness were analyzed. The fire resistance of the RC slabs was defined by 'ultimate strength design' criteria as used in all modern concrete design codes. Results obtained from 'simplified' calculation method, described in Eurocode 2 part 1.2, and by using the software FIRE are presented and compared in this paper.