scholarly journals Cyclic Testing of Concrete-Filled Double-Skin Steel Tubular Column to Steel Beam Joint with RC Slab

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Dongfang Zhang ◽  
Junhai Zhao ◽  
Shuanhai He
Keyword(s):  
Energy Dissipation ◽  
Failure Modes ◽  
Compressive Force ◽  
Steel Beam ◽  
Composite Joints ◽  
Equivalent Viscous Damping ◽  
Rc Slab ◽  
Bare Steel ◽  
Double Skin ◽  
Rc Slabs

The design of composite joints for connecting concrete-filled double-skin tubular (CFDST) columns to steel beams supporting reinforced concrete (RC) slabs is presented in this paper. Five half-scale specimens were designed, including four composite joints with RC slab and one bare steel beam joint, and were tested under a constant axially compressive force and lateral cyclic loading at the top end of the column to evaluate their seismic behavior. The main experimental parameters were the construction of the joint and the type of the column. The seismic behaviors, including the failure modes, hysteresis curves, ductility, strength and stiffness degradation, and energy dissipation, were investigated. The failure modes of the composite joints depended on the joint construction and on the stiffness ratio of beams to columns. Joints of stiffening type had significantly higher load-bearing and deformation capacities than joints of nonstiffening type. Compared with the bare steel beam joint, the bearing capacities of the composite joints with RC slabs were markedly increased. The composite action was remarkable under sagging moments, resulting in larger deformation on the bottom flanges of the beams. Overall, most specimens exhibited full hysteresis loops, and the equivalent viscous damping coefficients were 0.282∼0.311. The interstory drift ratios satisfied the requirements specified by technical regulations. Composite connections of this type exhibit excellent ductility and favorable energy dissipation and can be effectively utilized in superhigh-rise buildings erected in earthquake zones.

Seismic Performance of Medium Thick-Walled Cold-Formed Steel Top-and-Seat Angle Joint

2014 ◽  
Vol 501-504 ◽  
pp. 1609-1614
Author(s):  
Zhong Peng ◽  
Jun Huang ◽  
Shao Bin Dai ◽  
Ji Xiong Liu
Keyword(s):  
Energy Dissipation ◽  
Failure Modes ◽  
Mechanical Performance ◽  
High Strength ◽  
Initial Stiffness ◽  
Element Analysis ◽  
Equivalent Viscous Damping ◽  
Seat Angle ◽  
Cold Formed Steel ◽  
Energy Dissipation Capacity

3 medium thick-walled cold-formed steel top-and-seat angle joints were designed. The ABAQUS nonlinear finite element analysis on earthquake resistance behaviors of the joints were conducted under low cyclic loading. The results indicate that the failure processes and failure modes of 3 specimens are basically the same, the destruction of joints derive from buckling deformation of the top-and-seat angle and buckling of the steel beam flanges; the shapes of hysteresis curves of all specimens are obvious pinch together and present spindle, the displacement ductility factors are greater than 5.5, the equivalent viscous damping factors are greater than 0.158, all the specimens possess good energy dissipation capacity. The secant stiffness variations are almost similar, each specimen represents significant degradation. Increase the thickness of angle and diameter of high-strength bolt can improve the mechanical performance of the joints. Increase the bolt diameter, the ductility, energy dissipation capacity and initial stiffness enhance obviously, however, there is no apparent effect while increasing the thickness of angle.

scholarly journals Experimental and Numerical Investigation of Concrete-Filled Double-Skin Steel Tubular Column for Steel Beam Joints

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Dongfang Zhang ◽  
Junhai Zhao ◽  
Yufen Zhang
Keyword(s):  
Failure Modes ◽  
Compressive Force ◽  
Load Level ◽  
Steel Beams ◽  
Initial Stiffness ◽  
Element Analysis ◽  
Fea Model ◽  
Failure State ◽  
Double Skin ◽  
The Moment

This paper presents a new type of joint for connecting steel beams with a concrete-filled double-skin steel tubular (CFDST) column. Four half-scale specimens of the joint with different specifications were constructed and tested under a constant axially compressive force with vertical low-reversal loads applied to the beam ends to examine their failure modes and hysteretic behaviors. The beam hinging mechanism of the joint was observed in the radian area of the horizontal end plates. The proposed connection was found to exhibit good energy dissipation capabilities with its limit rotation in the failure state reaching 0.05 rad, thus satisfying the FEMA-350 ductility requirement of ≥0.03 rad for seismic resistance. A finite element analysis (FEA) model of the joint was also established and validated by comparing its predictions with experimental results. The FEA model was used to investigate the effects of different parameters such as the stiffened height of the web anchorage plate, axial load level, steel and concrete strengths, steel ratio on the moment-rotation relationship, and initial stiffness of the connection. This paper presents some important design considerations of the connection, as well as aspects requiring further study.

scholarly journals Damage Assessment of Two-Way Bending RC Slabs Subjected to Blast Loadings

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Haokai Jia ◽  
Ling Yu ◽  
Guiying Wu
Keyword(s):  
Damage Assessment ◽  
Failure Modes ◽  
Negative Reinforcement ◽  
Research Work ◽  
Design Parameters ◽  
Modeling And Analysis ◽  
Blast Response ◽  
Rc Slab ◽  
Rc Slabs ◽  
Blast Loadings

Terrorist attacks on vulnerable structures and their individual structural members may cause considerable damage and loss of life. However, the research work on response and damage analysis of single structural components, for example, a slab to blast loadings, is limited in the literature and this is necessary for assessing its vulnerability. This study investigates the blast response and damage assessment of a two-way bending reinforced concrete (RC) slab subjected to blast loadings. Numerical modeling and analysis are carried out using the commercial finite element code LS-DYNA 971. A damage assessment criterion for the two-way bending RC slab is defined based on the original and residual uniformly distributed load-carrying capacity. Parametric studies are carried out to investigate the effects of explosive weight and explosive position on the damage mode of the two-way RC slab. Some design parameters, such as the boundary conditions and the negative reinforcement steel bar length, are also discussed. The illustrated results show that the proposed criterion can apply to all failure modes. The damage assessment results are more accurate than the ones due to the conventional deformation criterion.

scholarly journals EXPERIMENTAL STUDY ON SEISMIC PERFORMANCE OF PEC COMPOSITE COLUMN-STEEL BEAM FRAME WITH WELDED T-STUB STRENGTHENED CONNECTIONS

2021 ◽  
Keyword(s):  
Energy Dissipation ◽  
Failure Mode ◽  
Seismic Performance ◽  
Damping Ratio ◽  
Plastic Hinge ◽  
Frame Structure ◽  
Steel Beam ◽  
Lateral Stiffness ◽  
Equivalent Viscous Damping ◽  
Composite Frame

Seismic performance of innovative Partially Encased Composite (PEC) column-steel beam composite frame was investigated, where the connection was strengthened by the welded T-stub. A ½ scale, two-storey, and one bay composite frame specimen was designed and fabricated for the quasi-static test. Through the experimental observation and measurements, the seismic performance were evaluated, including hysteretic characteristic, lateral stiffness, seismic energy dissipation, and ductility. The plastic damage evolution process and ductile failure mode were clarified. The results indicated that the welded T-stud strengthened connection enhanced the integrity of the frame and led to higher seismic strength and larger lateral stiffness. The plastic hinge was observed away from the beam end due to the welded T-stud and the specimen exhibited an approximately completed hysteretic loop. Without significant decreasing of the ultimate bearing capacity, its overall drift, ductility efficient and equivalent viscous damping ratio were 3.63% (push) / 4.07% (pull), 3.21 (push) / 3.70 (pull) and 0.261 respectively. The proposed structure possesses sound deformation, ductility, and energy-dissipation capacity with the desired plastic failure mode induced by the plastic hinges formed in all beam sections near the T-stud end and column section at the bottom, successively. It was demonstrated an ideal ductile energy-dissipation mode of the frame structure.

Research on seismic behavior of special-shaped CFST column to H-section steel beam joint

2021 ◽  
pp. 136943322110073
Author(s):  
Yu Cheng ◽  
Yuanlong Yang ◽  
Binyang Li ◽  
Jiepeng Liu
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Seismic Behavior ◽  
Failure Modes ◽  
Joint Stiffness ◽  
Load Ratio ◽  
Element Model ◽  
Steel Tube ◽  
Steel Beam ◽  
Static Test

To investigate the seismic behavior of joint between special-shaped concrete-filled steel tubular (CFST) column and H-section steel beam, a pseudo-static test was carried out on five specimens with scale ratio of 1:2. The investigated factors include stiffening types of steel tube (multi-cell and tensile bar) and connection types (exterior diaphragm and vertical rib). The failure modes, hysteresis curves, skeleton curves, stress distribution, and joint shear deformation of specimens were analyzed to investigate the seismic behaviors of joints. The test results showed the connections of exterior diaphragm and vertical rib have good seismic behavior and can be identified as rigid joint in the frames with bracing system according to Eurocode 3. The joint of special-shaped column with tensile bars have better seismic performance by using through vertical rib connection. Furthermore, a finite element model was established and a parametric analysis with the finite element model was conducted to investigate the influences of following parameters on the joint stiffness: width-to-thickness ratio of column steel tube, beam-to-column linear stiffness ratio, vertical rib dimensions, and axial load ratio of column. Lastly, preliminary design suggestions were proposed.

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.

Reliability analysis of shear connection in composite beams with profiled steel sheeting

2011 ◽  
Vol 8 (1) ◽  
pp. 29-34
Author(s):  
M. Youcef ◽  
M. Mimoune ◽  
F. Mimoune
Keyword(s):  
Reliability Analysis ◽  
Failure Modes ◽  
Composite Beams ◽  
Steel Beam ◽  
British Standard ◽  
Shear Connectors ◽  
Shear Connection ◽  
Composite Slabs ◽  
European Code ◽  
Headed Stud

This paper describes the reliability analysis of shear connection in composite beams with profiled steel sheeting. The profiled steel sheeting had transverse ribs perpendicular to the steel beam. The level of safety of shear connection, and failure modes were determinate. An extensive parametric study was conducted to study the effects on the safety and behaviour of shear connection by changing the profiled steel sheeting geometries, the diameter and height of headed stud, as well as the strength of concrete. We compared the level safety calculated using the American specification, British standard and European code for headed stud shear connectors in composite slabs with profiled steel sheeting perpendicular to the steel beam. It is found that the design overestimated the level safety of shear connection.

Interactive shear resistance of corrugated web in steel beam exposed to fire

2016 ◽  
Vol 7 (1) ◽  
pp. 69-78
Author(s):  
Mariusz Marcin Maslak ◽  
Marcin Lukacz
Keyword(s):  
Failure Modes ◽  
Steel Beams ◽  
Steel Beam ◽  
Safety Level ◽  
Design Algorithm ◽  
Content Type ◽  
Corrugated Webs ◽  
Buckling Resistance ◽  
Corrugated Web ◽  
Shear Buckling

Purpose The purpose of this paper is to present and discuss in detail the design approach to shear buckling resistance evaluation for corrugated web being a part of a steel beam exposed to fire. Design/methodology/approach It is based on the interaction between the local and global elastic instability failure modes as well as on the possible yielding of the whole web cross-section during fire. Findings New formulae, adequate for specification of the suitable shear buckling coefficients, depend not only on the web slenderness but also on the temperature of structural steel. Originality/value The methodology proposed by the authors can be added to the current European standard recommendations given in EN 1993-1-2 as a well-justified design algorithm helpful in reliable evaluation of a safety level for steel beams with slender corrugated webs subject to fire exposure. It seems to be highly desirable because, at present, there are no detailed instructions in this field.

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