Cyclic behavior of T-stub connection to hollow section steel column using TSOBs

This paper aims to numerically investigate the cyclic behavior of retrofitted and non-retrofitted circular hollow section (CHS) T-joints under axial loading. Different joints with varying ratios of brace to chord radius are studied. The effects of welding process on buckling instability of the joints in compression and the plastic failure in tension are considered. The finite element method is employed for numerical analysis, and the SAC protocol is considered as cyclic loading scheme. The CHS joints are retrofitted with different numbers of Fiber Reinforced Polymer (FRP) layers with varying orientation. The results show that the welding process significantly increases the plastic failure potential. The chord ovalization is the dominant common buckling mode under the compression load. However, it is possible to increase the energy dissipation of the joints by utilizing FRP composite through changing the buckling mode to the brace overall buckling.

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Tests of Inclined Concrete-Filled Steel Tubular Stub Columns under Vertical Cyclic Loading

Advances in Civil Engineering ◽

10.1155/2018/5426731 ◽

2018 ◽

Vol 2018 ◽

pp. 1-9 ◽

Cited By ~ 3

Author(s):

Chayanon Hansapinyo ◽

Chinnapat Buachart ◽

Preeda Chaimahawan

Keyword(s):

Cyclic Loading ◽

Local Buckling ◽

Steel Tube ◽

Cyclic Behavior ◽

Cross Sectional ◽

Tubular Columns ◽

Steel Column ◽

Inclination Angles ◽

Inclined Angle ◽

Stub Columns

This paper presents an experimental study on the cyclic behavior of fifteen concrete-filled steel tubular columns subjected to vertical cyclic loading. All test samples’ cross-sectional area is 75 × 75 mm2square, and they are 500 mm long. The main variables in the test are the thickness of the steel tube (1.8 and 3.0 mm with the width-to-thickness ratios (b/t) of 41.7 and 25), the strength of the infilled concrete (no-fill, 23 MPa, and 42 MPa), and the inclined angle (0, 4, and 9 degrees). The results show that all samples failed due to local buckling in compression followed by tearing of the steel tube in tension. The inclination angles of 4 and 9 degrees decreased the vertical compressive capacity of the 1.8 mm vertical hollowed steel column by 34 and 39 percent, respectively. However, the infilled concrete and thicker tube (3.0 mm) could substantially reduce the adverse effect of the inclination angle. The compressive ductility of the hollowed column with the thinner tube was significantly enhanced by the infilled concrete as well.

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Cyclic Behavior of Hollow Section Beam–Column Moment Connection: Experimental and Numerical Study

Metals ◽

10.3390/met10121608 ◽

2020 ◽

Vol 10 (12) ◽

pp. 1608

Author(s):

Eduardo Nuñez ◽

Nwar Boainy ◽

Freddy González ◽

Ronald Torres ◽

Ricardo Picón ◽

...

Keyword(s):

Numerical Model ◽

Large Scale ◽

Numerical Study ◽

Local Buckling ◽

Cyclic Behavior ◽

Steel Buildings ◽

Moment Connections ◽

Hollow Section ◽

Moment Connection ◽

Ductile Behavior

Steel buildings with tubular columns showed a satisfactory performance during the Honshu (2011) earthquake, unlike steel buildings in the 1994 Northridge and 1995 Kobe earthquakes, where welded moment connections showed damage in their joints. In this research, a lateral joint using a hollow structural section (HSS)-beam and HSS-column subjected to cyclic displacement was performed. Three large-scale specimens were tested and a numerical model was calibrated, reaching a good adjustment. Later, several configurations of beams and columns were evaluated using finite element (FE) models from the numerical model previously calibrated. A flexural resistance higher 0.80 Mp at 0.04 [rad] was obtained for all cases studied. The ductility factor in the 3 specimens was lower than 2.5, therefore a non-ductile behavior was controlled in the connection. This aspect is very important although a 0.8 Mp at 0.04 [rad] was achieved. Finally, the typical welded moment connection can be improved using the bolted moment connection, which allows the concentration of inelastic incursion in the beam compared with the welded solution. However, a non-ductile behavior derived from local buckling in flanges of a tubular beam can affect the seismic performance.

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A Flexure-Shear Coupling Fiber-Section Model for the Cyclic Behavior of R/C Rectangular Hollow Section Bridge Piers

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.374-377.2009 ◽

2011 ◽

Vol 374-377 ◽

pp. 2009-2012

Author(s):

Ning Li ◽

Zhong Xian Li ◽

Li Li Xie

Keyword(s):

Nonlinear Behavior ◽

Simulation Models ◽

Constitutive Relationship ◽

Bridge Piers ◽

Cyclic Behavior ◽

Thin Wall ◽

Finite Element Program ◽

Hollow Section ◽

Element Program ◽

Shear Coupling

Reinforced concrete (R/C) bridge pier with hollow section may undergo strongly nonlinear responses when subjecting severe earthquakes. The pier may perform flexure-shear coupling behavior, especially for the thin wall of the hollow section. Some simulation models accounting flexure-axial coupled effects were proposed, however, few simulation model is proposed for R/C hollow section bridge piers mainly impacted by the flexure-shear coupling. In this paper a beam-column element accounting for flexure-shear effect is presented. The mathematical theory for this element is flexibility-based formulation, and the section constructed by fibers can be treated as any kind of bi-axial materials. The cyclic soften membrane model (CSMM) constitutive relationship for plane bi-axial R/C components is used in the determination of the nonlinear behavior. Two cyclic pushover experiments were carried on scaled hollow section piers. The results deduced from the numerical model is compared with the experiment result. This fiber-based model provides sufficient accuracy and computational efficiency. The model has been implemented into the finite element program, OpenSees. And further researches will focus on the flexure-shear induced damage and collapse for bridge structures.

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