Computerised interaction diagrams and moment capacity contours for composite steel–concrete cross-sections

2010 ◽  
Vol 32 (11) ◽  
pp. 3734-3757 ◽  
Author(s):  
C.G. Chiorean
Keyword(s):  
Cross Sections ◽  
Moment Capacity ◽  
Composite Steel

Slenderness Influence on the Behavior of Composite Columns

2016 ◽  
Vol 691 ◽  
pp. 40-50
Author(s):  
Štefan Gramblička ◽  
Andrea Hrusovska
Keyword(s):  
Cross Sections ◽  
Design Method ◽  
Tall Buildings ◽  
Concrete Columns ◽  
Order Theory ◽  
Second Order ◽  
Order Effects ◽  
Composite Columns ◽  
Steel Members ◽  
Composite Steel

Composite steel and concrete columns have been used in the tall buildings due theirs high-resistance and the possibility to reduce cross sections when we compered composite columns with reinforced concrete columns. There are a lot of types of composite columns. We are concerned with columns, which are completely or partially concrete-encased steel members. In practice, a lot of composite columns are relatively slender and in design the second - order effects will usually need to be included. A partially concrete encased steel cross-section was selected for laboratory tests of composite columns. According to the results of the experiments (total of 18 columns were tested in two series), we analyzed the effects of the second - order theory. The experimental results were compared with theoretical results obtained from the model developed in the non-linear software. The evaluation of the results is also shown in comparison with the general design method according to Eurocode 4, Design of composite steel and concrete structures - Part 1.1 General rules and rules for buildings.

scholarly journals On the New "Manual on Design of Composite Steel and Concrete Structures (in Elaboration of Formulary SP 266.13330.2016 "Composite Steel and Concrete Structures. Design Rules")"

2019 ◽  
pp. 99-106
Author(s):  
Sergey B. Krylov ◽  
Vladimir A. Semenov ◽  
Denis V. Konin ◽  
Alexey S. Krylov ◽  
Lidiya S. Rozhkova
Keyword(s):  
Cross Sections ◽  
Concrete Structures ◽  
Concrete Slabs ◽  
Steel Beams ◽  
Deformation Model ◽  
Normative Documents ◽  
Beam Columns ◽  
Steel Reinforced Concrete ◽  
Reinforced Concrete Slabs ◽  
Composite Steel

The paper provides a brief overview of domestic and foreign guidelines (manuals) for the design of composite steel and concrete structures: steel-concrete slabs on profiled flooring, combined beams, and columns with rigid reinforcement. The necessity of creation of the actual manual corresponding to the modernlevel of development of construction science, normative documents and design practiceslinked to the new formulary SP 266.1325800.2016 is proved. It will facilitate the design, reduce labor expenditures and improve the reliability of composite steel and concrete structures. The new guidance provides general recommendations for the design of composite steel and concrete structures and the basic regulations for the calculations. The new guidance describes recommendations for modeling of composite steel and concrete structures and elements in the calculated complexes, the recommendations for calculation of combined beams fully concreting rectangular and T-section, partially concreting along with support slab on the lower flange of the beam, columns with rigid reinforcement, shear a connection of composite beams. Recommendations on the registration of creep, shrinkage and crack formation in the appointment of the modulus of elasticity are given. Recommendations on the use of diagrams of the state of concrete, reinforcement, and steel in the calculation of steel-concrete elements on a nonlinear deformation model are given. Recommendations on the use of the range of sheet flooring for steel-reinforced concrete slabs, as well as metal profiles as steel beams and rigid reinforcement in the cross sections of columns and combined beams, are presented. Recommendations on a design of units and details of composite steel and concrete structures are given, refined recommendations on buffer are presented. The examples of connection of steel beams with columns with rigid reinforcement are given. The examples of calculation of composite steel and concrete structures taking subject to the recommendations given in the Manual are presented.

scholarly journals Lateral torsional buckling capacity of corroded steel beams: A parametric study

2021 ◽  
Vol 1201 (1) ◽  
pp. 012038
Author(s):  
G Kullashi ◽  
S C Siriwardane ◽  
M A Atteya
Keyword(s):  
Cross Sections ◽  
Parametric Study ◽  
Analytical Framework ◽  
Reduction Factor ◽  
Steel Beams ◽  
Uniform Corrosion ◽  
Lateral Torsional Buckling ◽  
Torsional Buckling ◽  
Moment Capacity ◽  
The Moment

Abstract Thickness reduction due to uniform corrosion increases the tendency of lateral torsional buckling (LTB) of open cross-sections and it reduces the moment capacity of the beam. The effect of the various corrosion cases on the LTB moment capacity (M b,rd) of the I-beams are investigated in this paper. An analytical framework for patch corroded I-beams is introduced to provide a guideline for simulating the nonlinear lateral torsional buckling behaviour of patch corroded simple beams. Hence the effect of different corrosion scenarios to reduce the buckling reduction factor (η LT) is investigated by conducting a parametric study. Twelve different beam lengths were considered to obtain different non-dimensional slenderness ratios (λ LT) in this parametric study. The degraded buckling curves were obtained for each corrosion scenarios.

scholarly journals Bending Resistance of Composite Sections with Nonductile Shear Connectors and Partial Shear Connection

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Svetlana M. Kostic ◽  
Biljana Deretic-Stojanovic
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Bending Moment ◽  
Nonlinear Material ◽  
Parameter Study ◽  
Shear Connectors ◽  
Shear Connection ◽  
The Cross ◽  
Section Analysis ◽  
Composite Steel

The paper presents the nonlinear section analysis for composite steel-concrete beams with different degrees of shear connection. The analysis is fiber based, i.e., integration over the cross section is performed numerically, and any uniaxial nonlinear material model can be assigned to the steel and concrete parts of the cross section or to the reinforcement bars. The analysis assumed full interaction between steel and concrete and therefore, is suitable for analysis of composite steel-concrete beam cross sections with nonductile shear connectors. Its accuracy is verified on few experimental results. The presented section analysis is used in the parameter study in order to evaluate different methods proposed by design codes for determining the bending moment resistance of composite cross sections with nonductile shear connectors and different degrees of shear connection. The following effects are considered: variation of concrete and steel material models, presence of slab reinforcement, and creep of concrete. Special attention is paid on two different constructional methods: propped and unpropped. The weaknesses of the simplified design method in determining bending moment resistance are identified and recommendations for practical design analysis are formulated.

scholarly journals Determination of the Stress Increase of the Unbonded Tendon in a Continuous Concrete Beam at Ultimate Capacity Using Nonlinear Analysis

2021 ◽  
Vol 64 (1) ◽  
pp. 109-128
Author(s):  
Tarja Nakari ◽  
Anssi Laaksonen
Keyword(s):  
Nonlinear Analysis ◽  
Cross Sections ◽  
Concrete Beam ◽  
Continuous Beam ◽  
Ultimate Capacity ◽  
Moment Capacity ◽  
Stress Increase ◽  
Moment Redistribution ◽  
The Moment ◽  
Post Tensioned

Abstract Predicting the stress increase of an unbonded tendon in a post-tensioned continuous concrete beam at ultimate capacity is more difficult than when bonded tendons are used. The failure mechanisms of the continuous beam are also different to that of the simple-span beam. The loading type, ductility of the support area and moment redistribution influence the behaviour of the continuous structures. In this research, the simplified nonlinear analysis was used for predicting the unbonded tendon stress increase at ultimate capacity in continuous two-span beams. The model is based on the moment-curvature relationships of the reinforced concrete cross-sections under different compressive forces and deformations of the continuous beam under loading. The results have been compared with the experimental results of recent studies found in the literature. In addition, 92 unbonded post-tensioned two-span beams with different reinforcements have been examined by using the model and compared to the results obtained from empirical equations from the literature. The results from the nonlinear analysis correspond well to the results from the other models up to the reinforcement ratio of 0.35. The calculated values of the maximum moment capacity at the centre support were close to the results from the test beams.

scholarly journals SHORT-TIME ANALYSIS OF Re BEAMS STRENGTBENED WITH OR WITHOUT FRP PLATES

2017 ◽  
Vol 19 (1) ◽  
pp. 31
Author(s):  
Jorge Luis Palomino Tamayo
Keyword(s):  
Compressive Strength ◽  
Cross Sections ◽  
Design Parameters ◽  
Time Analysis ◽  
Concrete Compressive Strength ◽  
Flexural Capacity ◽  
Moment Capacity ◽  
Flexural Response ◽  
Original Strength ◽  
Short Time

ABSTRACTThe analytical model proposed by Bazant & Oh based on compatibility of deformations and equilibrium of forces in RC cross sections is extended and presented to predict short-time deformations. Stresses and deflections in beams strengthened with 01' without FRP plates epoxy- bonded to the tension face of rectangular and T cross sections. The theory assumes concrete to have a nonzero tensile carrying capacity. A parametric study was conducted to invesugate some design parameters such as plate area. plate stiffness and strength, concrete compressive strength and steel reinforcement ratio. To this end. moment-curvat ure diagrams lI'ere generated to know the influence of such parameters in the flexural response of the section. In all cases studied, adding the plate to the cross section increases the yield and ultimate tnoment capacity substantially in sections with a low steel reinforcenient ratio in tension being this increase more significant in doubly RC sections rather than in singly ones. Furthermore, results indicate that this increased flexural capacity could vary from 1.1 to 3.3 times the original strength of the section. Finally, the increase of concrete compressive strength does not increase the ultimate moment capacity significantly as it does when it is accompanied with the plate. Results show that the increased flexural capacity due to combined action could be as high as 4 times the original strength of the section. Keywords.-Short-time, Analysis, FRP plate, Stress, Strain. RESUMENSe extiende y presenta e! modelo analítico propuesto por Bazant & Oh basado en la compatibilidad de deformaciones y equilibrio de fuerzas en secciones de concreto armado para predecir deformaciones, esfuerzos y deflexiones instantáneas en vigas con o sin láminas de FRP adheridas con epóxico las secciones transversales rectangulares en forma T. La teoría supone que el concreto tiene capacidad de resistir esfuerzos en tensión. Se llevó a cabo un estudio paramétrico para investigar algunos parámetros de diseño tales como el área de la lámina, resistencia y rigidez de la lámina, resistencia a la compresión del concreto y cuantía del acero de refuerzo. Para este fin, se generaron diagramas de momento-curvatura para conocer la influencia de estos parámetros en la respuesta de flexión de la sección. En todos los casos estudiados, la adición de la lámina a la sección transversal incrementa la capacidad del momento de fluencia sustancialmente en secciones con baja cuantía de refuerzo en tensión, siendo este incremento más significativo en secciones doblemente reforzadas que en simplemente reforzadas. Además, los resultados indican que la capacidad a flexión incrementada podría variar de 1.1 a 3.3 veces la resistencia original de la sección Finalmente, .el incremento-en la resistencia a la compresión de! concreto no se incrementa la capacidad del último momento-significativamente como cuando se le acompaña con la lámina. Los resultados muestran que la capacidad de flexión es incrementada debido a la acción combinada, esta podría ser tan alta como 4 veces la resistencia original de la sección.. Palabras clave.- Instantáneo, Análisis, Lámina de FRP, Esfuerzo, Deformación.

scholarly journals A COMPUTER METHOD FOR MOMENT-CURVATURE ANALYSIS OF COMPOSITE STEEL-CONCRETE CROSS-SECTIONS OF ARBITRARY SHAPE

2017 ◽  
Vol 9 (1) ◽  
pp. 25-40 ◽  
Author(s):  
Cosmin G. CHIOREAN
Keyword(s):  
Axial Force ◽  
Cross Sections ◽  
Bending Moment ◽  
Computer Method ◽  
Computational Time ◽  
Equilibrium Equations ◽  
Curvature Analysis ◽  
Assumed Strain ◽  
Initial Starting ◽  
Composite Steel

This paper presents a new computer method for moment-curvature analysis of arbitrary-shaped composite steel-concrete cross-sections that are subjected to biaxial bending and axial force. The complete moment-curvature diagrams are determined such that axial force and bending moment ratio is kept constant. A strain-driven algorithm has been developed, the solution of the nonlinear equilibrium equations is controlled by the assumed strain values in the most compressed point and by solving just two coupled nonlinear equations. Such an approach may be used to assess accurately the main features of the elasto-plastic behaviour of composite cross-sections: multiple yielding points associated to different materials, flexural and axial rigidity, moment-curvature relationship in pre and post-critical domain and curvature ductility detecting also unloaded regions of the cross-sections that may occur even under monotonically increasing of the total bending moment. Since the Jacobian’s of the resulted nonlinear system of equations is always positive definite the convergence stability is not sensitive to the initial/starting values of the iterative process and to the strain softening exhibited by the concrete in compression. By using a path integral technique on boundary of cross-section area, gradual spread of plasticity and residual stress distribution assumed for encased steel elements are accurately considered reducing also the computational time significantly. In order to illustrate the proposed method and its accuracy and efficiency, a computer program has been developed and used to study several representative examples. The numerical studies presented and comparisons made prove the effectiveness and time saving of the proposed method of analysis.

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