scholarly journals Numerical Analysis of Seismic Performances of Post-Fire Scoria Aggregate Concrete Beam-Column Joints

Fire ◽  
2021 ◽  
Vol 4 (4) ◽  
pp. 70
Author(s):  
Bin Cai ◽  
Wen-Li Hu ◽  
Feng Fu
Keyword(s):  
Heat Transfer ◽  
Seismic Behavior ◽  
Seismic Analysis ◽  
Reinforcement Ratio ◽  
Heat Transfer Analysis ◽  
Longitudinal Reinforcement ◽  
Aggregate Concrete ◽  
Axial Compression Ratio ◽  
Energy Dissipation Capacity ◽  
Simulation Results

In order to analyze the post-fire seismic performances of scoria aggregate concrete (SAC) beam-column joints precisely and effectively, one finite element model (FEM) was developed to simulate the seismic behavior of SAC beam-column joints. The FEM consists of two sequential parts: firstly, the heat transfer analysis of the beam-column joints, and then the seismic analysis of the SAC joints by combining the temperature field distribution obtained from the heat transfer analysis with the mechanical properties of the SAC after fire, both of which were implemented in ABAQUS. In order to make the simulation results more accurate, spring elements were applied to simulate the bond–slip behavior with material degradation due to fire damage in the simulation of seismic analysis. Moreover, in order to validate the FEM, the seismic behavior of the natural aggregate concrete (NAC) beam-column joints after fire was simulated with the established FEM, and the simulation results were compared with the available test data. It is proved that the FEM we built was accurate and effective and provided efficient solutions for evaluating the seismic performance of post-fire beam-column joints so that the effects of various parameters, namely, fire time, longitudinal reinforcement ratio, and axial compression ratio on the seismic performance of SAC beam-column joints after fire were investigated in depth, which indicated the increase of axial compression ratio can improve the strength, initial stiffness, and energy dissipation capacity of SAC joints, while the increase of longitudinal reinforcement ratio can increase the strength and stiffness of SAC joints to a small extent, but too high reinforcement ratio will significantly weaken the energy dissipation capacity of SAC joints.

Research on the Joint of Concrete-Filled Steel Tubular Column and Steel Beam

2013 ◽  
Vol 351-352 ◽  
pp. 174-178
Author(s):  
Ying Zi Yin ◽  
Yan Zhang
Keyword(s):  
Energy Dissipation ◽  
Failure Mechanism ◽  
Compression Ratio ◽  
Seismic Behavior ◽  
Strength Degradation ◽  
Steel Beam ◽  
Failure Characteristics ◽  
Static Test ◽  
Axial Compression Ratio ◽  
Energy Dissipation Capacity

With the pseudo-static test of 4 concrete-filled square steel tubular column and steel beam joint with outer stiffened ring, this paper discusses the failure characteristics, failure mechanism and seismic behavior of joints under different axial compression ratio. The analysis of the testing results shows: when reached the ultimate strength, the strength degradation and stiffness degradation of joints are slowly and the ductility is also good, the energy dissipation capacity of joints is much better.

Research on the Seismic Behavior of Concrete-Filled Steel Tubular Column and Steel Beam Joint

2012 ◽  
Vol 204-208 ◽  
pp. 2528-2532
Author(s):  
Ying Zi Yin ◽  
Yan Zhang
Keyword(s):  
Energy Dissipation ◽  
Compression Ratio ◽  
Seismic Behavior ◽  
Steel Beam ◽  
Failure Characteristics ◽  
Static Test ◽  
Axial Compression Ratio ◽  
Earthquake Action ◽  
Energy Dissipation Capacity ◽  
Strength And Stiffness

Joints are the forces cross points of members, and the bearing modes are more complex than other members, especially under earthquake action, so the rationality of joints are directly related to the safe reliability of structure. By the pseudo-static test of 4 concrete-filled square steel tubular column and steel beam joint with outer stiffened ring, this paper discusses the failure characteristics, failure mechanism and seismic behavior of joints under different axial compression ratio. The analysis of the testing results shows: the energy dissipation capacity of joints is much better, the degradation of strength and stiffness are slowly when reached the ultimate strength, and the ductility is also good.

Heat Transfer Analysis of the High-Power LED Lamp With Liquid-Cooled Package

2010 ◽  
Author(s):  
Rong-Yuan Jou
Keyword(s):  
Heat Transfer ◽  
High Power ◽  
Silicone Oil ◽  
Thermal Design ◽  
Heat Transfer Analysis ◽  
Experimental Measurements ◽  
Thermal Imager ◽  
Simulation Results ◽  
Temperature Responses ◽  
Temperature And Flow Fields

In this study, the technique of immersed LEDs in ambient fluids of air, silicone oil or FC-40, respectively, to cool the LEDs which will generate large amount of heat in operation is investigated by methodologies of experimental measurements and numerical simulations. In experiments, three powers are sequentially input to the LEDs and three fluids, air, silicone oil, and FC-40, respectively, are used to cool the LEDs immersed in these fluids. Temperatures are measured by TCs and IR thermal imager. Detailed temperature and flow fields inside the lamp enclosure are analyzed, and results are compared to experimental measurements. Inclinations of LED lamp in four orientations of 0, 90, 135, 180, respectively, are studied to explore the inclination effects to thermal design of LED lamp. Simulation results found that it is not significant to the LEDs temperature responses. Thermal resistances Rja of the liquid-cooled package of LED lamp are calculated from simulation results, and it is around 13.7 °C/W in this design. In illuminance measurements, measured illuminances show tendency of reciprocal to distance square and proportional to the luminous intensity which is similar to the illuminance principle, and its values are in the sequence of 5W>4W>3W for three kinds of fluids. Basically, illuminances for air, FC-40, and silicone oil fluids are in the sequence of air>FC-40>silicone oil.

Experimental Study on the Seismic Behavior of SRHSC Columns

2011 ◽  
Vol 243-249 ◽  
pp. 366-369 ◽  
Author(s):  
Shan Suo Zheng ◽  
Qing Lin Tao ◽  
Yi Hu ◽  
Lei Li ◽  
Zhi Qiang Li
Keyword(s):  
High Strength Concrete ◽  
Seismic Behavior ◽  
Concrete Strength ◽  
High Strength ◽  
Relationship Strength ◽  
Composite Columns ◽  
Axial Compression Ratio ◽  
Energy Dissipation Capacity ◽  
Strength And Stiffness ◽  
Ductility Capacity

Based on the experiments of 4 SRHSC (steel reinforced high strength concrete) column specimens, which were different in concrete strength, axial compression ratio and spacing of hoop reinforcement, this paper investigates the seismic behavior and flexural strength of SRHSC columns under cyclic lateral loading which is controlled by the displacement. According to the date and phenomenon of experiment, adopting existed theory and foreign codes for composite columns, the failure mode, lateral load-deflection relationship, strength and stiffness deterioration, ductility capacity and energy dissipation capacity of SRHSC columns is analyzed.

A Study on Parameters Affect Seismic Behavior of Reinforced Concrete Specially Shaped Columns

2010 ◽  
Vol 163-167 ◽  
pp. 1300-1306
Author(s):  
Pu Yang ◽  
Jing Tang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Reinforced Concrete ◽  
Energy Dissipation ◽  
Cross Section ◽  
Seismic Behavior ◽  
Analytical Study ◽  
Longitudinal Reinforcement ◽  
Strength Capacity ◽  
Energy Dissipation Capacity

Using flexibility-based finite element method based on fiber model, several experiments of reinforced concrete specially shaped columns under cyclic loading which cross section is ‘L’, ‘T’ and ‘+’ shape with different longitudinal reinforcement and hoop reinforcement have been simulated, and the seismic behavior of columns such as strength, ductility and energy dissipation are analyzed. Results from the analytical study indicate that: 1) ductility of the column increases as quantity of hoop reinforcement increases. 2) strength capacity of the column increase linearly as ratio of longitudinal reinforcement increase, but is not seriously affected by hoop reinforcement; 3) energy dissipation capacity of the column is not significantly affected by hoop and longitudinal reinforcement, particularly in slightly nonlinear range.

Experimental and numerical study of reinforced concrete interior wide beam-column joints subjected to lateral load

2018 ◽  
Vol 45 (11) ◽  
pp. 947-957 ◽  
Author(s):  
Sara Mirzabagheri ◽  
Abbas Ali Tasnimi ◽  
Fadwa Issa
Keyword(s):  
Reinforced Concrete ◽  
Seismic Behavior ◽  
Numerical Study ◽  
Cyclic Loads ◽  
Longitudinal Reinforcement ◽  
Wide Beam ◽  
Mode Of Failure ◽  
Energy Dissipation Capacity ◽  
Wide Beams ◽  
Brittle Mode

Past researches showed that the energy dissipation capacity of the wide beam-column joints was not sufficient. So, two full-scale reinforced concrete interior wide beam-column joints were tested under quasi-static cyclic loads and the performance of the specimens was studied experimentally and numerically. Effect of using wide beams in two directions was investigated and it became clear that the longitudinal reinforcement of transverse wide beam had significant effect on the seismic behavior of the joints. Flexural hinging mechanism in the wide beams occurred instead of torsion brittle mode of failure. Effect of eccentric beams on joints is one of the areas needing research in ACI 352R-02. In the numerical study, it was seen that damage of the joints was concentrated to one side of the joints that the beams shifted to. Besides, concrete grade did not have much effect on behavior of the joint.

Numerical Simulation on Beating Capacity of Steel Reinforced Light Aggregate Concrete Beam

2013 ◽  
Vol 351-352 ◽  
pp. 148-151
Author(s):  
Jun Jie Zhang ◽  
Qiu Yuan Zhang
Keyword(s):  
Numerical Simulation ◽  
Tensile Stress ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Longitudinal Reinforcement ◽  
Concrete Member ◽  
Aggregate Concrete ◽  
Loading Mode ◽  
Asymmetric Loading ◽  
Simulation Results

For a better analysis of the deformation of the steelreinforced light aggregate concrete member, adopt asymmetric loading mode,carry on numerical simulation of bearing capacity of steel reinforced lightaggregate concrete beams. The simulation results show that the: In theasymmetric loads, longitudinal reinforcement of the bottom of the beam both ends of the constrained position, due tothe presence of constraints, make it tensile stress,in the 250mmposition is tensile stress minimum, compressive stress correspondingly larger.In the central beam downward bending deformation, this part of the lower edgeof the beam longitudinal reinforcement tensile stress.

scholarly journals Seismic Behavior of RC Beam Column Joints with 600 MPa High Strength Steel Bars

2020 ◽  
Vol 10 (13) ◽  
pp. 4684
Author(s):  
Jian Feng ◽  
Shuo Wang ◽  
Marco Meloni ◽  
Qian Zhang ◽  
Jingwen Yang ◽  
...  
Keyword(s):  
Energy Dissipation ◽  
Axial Compression ◽  
High Strength Steel ◽  
Seismic Behavior ◽  
Failure Modes ◽  
High Strength ◽  
Longitudinal Reinforcement ◽  
Seismic Properties ◽  
Steel Bars ◽  
Energy Dissipation Capacity

This paper presents an experimental investigation of the seismic performance of interior beam–column joints with beams reinforced with Grade 600MPa longitudinal steel bars. Six full-scale reinforcement concrete (RC) interior joints are designed with different axial compression ratios and longitudinal reinforcement ratios, which are tested under reversed cyclic loading. Failure modes, hysteretic curves, skeleton curves, energy dissipation capacity, and the ductility of joints are investigated systematically. Moreover, the effect of the different axial compression ratios and longitudinal reinforcement ratios on the seismic behavior of the joints are deeply studied. Comparisons performed between specimens demonstrate that among the beam–column joints with 600 MPa high strength steel bars, specimens with high reinforcement ratios have better energy dissipation capacity, slower stiffness degradation, and lower ductility. Moreover, with the increase of the axial compression ratios, the energy dissipation capacity and ductility become weaker. The test results show the favorable seismic properties of beam–column joints equipped with 600 MPa high strength steel bars, which can be regarded as the research basis of the popularization and application of 600 MPa high strength steel bars in reinforcement concrete frame structures.

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