Browsing by Author "Benlakehal, Nourredine O."
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- Axial buckling resistance of partially encased columnsPublication . Abdelkadir, Fellouh; Benlakehal, Nourredine O.; Piloto, P.A.G.; Ramos Gavilán, Ana Belén; Mesquita, L.M.R.Partially Encased Columns (PEC) present good axial buckling resistance under fire, mainly due to the presence of concrete between flanges. The presence of concrete increases the mass and thermal inertia of the member and changes the variation of the temperature field within the cross section, in both the steel and concrete. The elastic buckling load of PEC under fire conditions may be calculated by the balanced summation method and by the finite element method. This work compares the results from both solution methods and provides the validation of the three dimensional model for different fire ratings of 30 and 60 minutes.
- Axial buckling resistance of partially encased columnsPublication . Abdelkadir, Fellouh; Benlakehal, Nourredine O.; Piloto, P.A.G.; Ramos Gavilán, Ana Belén; Mesquita, L.M.R.Partially Encased Columns (PEC) present good axial buckling resistance under fire, mainly due to the presence of concrete between flanges. The presence of concrete increases the mass and thermal inertia of the member and changes the variation of the temperature field within the cross section, in both the steel and concrete. The elastic buckling load of PEC under fire conditions may be calculated by the balanced summation method and by the finite element method. This work compares the results from both solution methods and provides the validation of the three dimensional model for different fire ratings of 30 and 60 minutes.
- Behaviour of industrial buildings with steel portal frames under fire conditionsPublication . Benlakehal, Nourredine O.; Bougara, Abdelkader; Fellouh, Abdelkadir; Piloto, P.A.G.Pitched roof Steel frame structures are widely used in industrial buildings for practical reasons of exploitation, durability and cost efficiency. However, steel although is a ductile material, it remains vulnerable to excessive temperatures. The recent accidents, which occurred in the industrial buildings of Sonatrach (petroleum industry in Algeria), in an urban area in Algiers or in an industrial zone in Skikda, remind us of the real danger and the potential risk of fire.
- Behaviour of industrial buildings with steel portal frames under fire conditionsPublication . Benlakehal, Nourredine O.; Bougara, Abdelkader; Fellouh, Abdelkadir; Piloto, P.A.G.Pitched roof Steel frame structures are widely used in industrial buildings for practical reasons of exploitation, durability and cost efficiency. However, steel being a ductile material, it remains vulnerable to excessive temperatures. The recent accidents, which occurred in the industrial buildings of Sonatrach (petroleum industry in Algeria), in an urban area in Algiers or in an industrial zone in Skikda, remind us of the real danger and the potential risk of fire.
- Buckling resistance of partially encased columns under firePublication . Piloto, P.A.G.; Hoffstaeter, Ricardo Anderson; Rigobello, Ronaldo; Soufyane, Amari; Benlakehal, Nourredine O.The fire resistance of partially encased columns depends on the temperature evolution during fire exposure. This work aims to evaluate the effect of the balanced summation model on the design of the buckling load of Partially Encased Columns under fire situation. New improvements will be presented to assess fire resistance, suggesting some modification in the Annex G of Eurocode EN 1994-1-2. The advanced calculation method is based on the 3D modelling of the Partially Encased Column, using steel profiles ranging from IPE200 to IPE500 and HEB160 to HEB500, and using different buckling lengths. An incremental and interactive procedure is used to solve the geometric and material non-linear behaviour. The temperature effect is taken into account, using the uncouple thermal-structural analysis. The results obtained by the numerical simulations are in good agreement with the new simple calculation method and are also useful to prescribe the buckling curve that best fits the 3D simulation results.
- Etude par simulation numérique du comportement des portiques métalliques en situation d’incendiePublication . Benlakehal, Nourredine O.; Lamri, Belkacem; Kada, Abdelhak; Mesquita, L.M.R.; Bouchair, AbdelhamidLes structures en portiques métalliques à double versants sont largement utilisées dans les bâtiments industriels pour des raisons pratiques d’exploitation, de durabilité et de rentabilité. Cependant le matériau acier quoi que ductile, il reste vulnérable aux excès de températures. Les récents événements d’incendies concernant les structures et bâtiments industriels de Sonatrach, à Alger dans une zone urbaine ou à Skikda dans une zone industrielle, nous rappellent le danger réel et le risque potentiel des incendies. Les nouvelles normes Européennes définissent des exigences actives et passives concernant le comportement au feu des hangars industriels. L’objectif de ce travail est d’étudier, par des simulations numériques, le comportement des portiques métalliques à double versants sous différents scénarios d’incendie. L’analyse numérique par la MEF et utilisant le logiciel ANSYS est considérée afin d’évaluer la résistance de ces structures et de rationaliser leur protection au feu. Une analyse, utilisant les non linéarités géométrique et matérielle, est conduite avec une variation progressive des températures jusqu’à la ruine. Différents taux de chargement ainsi que différents scénarios de feu seront utilisés pour évaluer la température critique ainsi que les déplacements des portiques en fonction de l’évolution de la température. Les résultats du modèle numérique sont comparés à ceux calculés par les méthodes simplifiées de l’Eurocode 3
- Finite element investigation on the behaviour of structural steel beams subjected to standard & parametric firePublication . Kada, Abdelhak; Lamri, Belkacem; Benlakehal, Nourredine O.; Mesquita, L.M.R.; Bouchair, AbdelhamidThis paper intends to present an investigation of the behaviour of steel beams under high temperatures rise due to fire using finite elements simulations with ANSYS software. Cases of study for solid as well as open web beams are considered and take into account uniform and transient temperature rise, material and geometric non-linear behaviour. Input fire scenarios are standard temperature-time curve ISO834 and parametric compartment fire model based upon Eurocode EN 1991-1-2. For the latter a comparison is made using the experimental results from BRE-Cardington tests data. Thermal and mechanical analysis is done using the effect of temperature dependent material properties and the Eurocode recommendations in estimating reduction mechanical steel properties. Three types of cellular beams are studied and the number of cells is shown to be critical for their behaviour under fire conditions. Results are related to temperature profiles in steel beam cross-sections, variation of displacements with respect to temperature change and critical temperatures.
- Fire performances of partially encased column subjected to eccentric loadingPublication . Fellouh, Abdelkadir; Bougara, Abdelkader; Piloto, P.A.G.; Benlakehal, Nourredine O.In this paper, the advanced and simplified calculation methods are used to evaluate the fire resistance of eccentrically loaded partially encased composite columns (PEC).
- Fire performances of partially encased column subjected to eccentric loadingPublication . Fellouh, Abdelkadir; Bougara, Abdelkader; Piloto, P.A.G.; Benlakehal, Nourredine O.In this paper, the advanced and simplified calculation methods are used to evaluate the fire resistance of eccentrically loaded partially encased composite columns (PEC). The work consists in developing an efficient Non-linear 3-D finite element model (ANSYS) to investigate the behaviour of Pin-ended PEC eccentrically loaded at elevated temperature. The columns were tested under standard ISO834 fire. The buckling load is determined for several column heights 3; 4.5 and 6 m, by considering an eccentricity around the minor axis equal to 0,5.B ; 1,0.B and 1,5.B (B base). The numerical method presented here is compared with the simple calculation method Annex G of EN 1994-1-2. The results show that after 50 min of fire exposure, the axial load capacity of PEC is reduced to more than half, which is a fair conclusion to take into consideration in structural fire design. The comparison results show a good agreement between the two methods at high fire ratings (R90 and R120), however at low fire rating (R30), the simple calculation method presents conservative results. It is to be concluded that the eccentricity of loading reduces the loadbearing capacity of the composite column. The shortest column (3m) presents the higher reduction in load bearing.
- Fire resistance of partially encased composite columns subjected to eccentric loadingPublication . Fellouh, Abdelkadir; Bougara, Abdelkader; Piloto, P.A.G.; Benlakehal, Nourredine O.Purpose – Investigate the fire performance of eccentrically loaded concrete partially encased column (PEC), using the advanced calculation method (ANSYS 18.2, 2017) and the simple calculation method in Annex G of Eurocode 4 (EN 1994-1-2, 2005). This work examines the influence of a range of parameters on fire behaviour of the composite column including: eccentricity loading, slenderness, reinforcement, fire rating and fire scenario. In this study, ISO-834 (ISO834-1, 1999) was used as fire source. Design/methodology/approach – Currently, different methods of analysis used to assess the thermal behaviour of composite column exposed to fire. Analytical method named simplified calculationmethods defined in European standard and numerical simulations named advanced calculation models are treated in this paper. Findings – The load-bearing capacity of the composite column becomes very weak in the presence of the fire accident and eccentric loading, this recommends to avoid as much as possible eccentric loading during the design of construction building. The reinforcement has a slight influence on the temperature evolution; moreover, the reinforcement has a great contribution on the load capacity, especially in combined compression and bending. When only the two concrete sides are exposed to fire, the partially encased composite column presents a high load-bearing capacity value. Originality/value – The use of a three-dimensional numerical model (ANSYS) allowed to describe easily the thermal behaviour of PEC columns under eccentric loading with the regard to the analytical method, which is based on three complex steps. In this study, the presence of the load eccentricity has found to have more effect on the load-bearing capacity than the slenderness of the composite column. Introducing a load eccentricity on the top of the column may have the same a reducing effect on the load-bearing capacity as the fire.
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