• Steel and Composite Structures
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• v.7 no.3
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• pp.185-200
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• 2007

Tubular construction is widely used in a range of civil and structural engineering applications. To date, the principal product range has comprised square, rectangular and circular hollow sections. However, hot-rolled structural steel elliptical hollow sections have been recently introduced and offer further choice to engineers and architects. Currently though, a lack of fundamental structural performance data and verified structural design guidance is inhibiting uptake. Of fundamental importance to structural metallic design is the concept of cross-section classification. This paper proposes slenderness parameters and a system of cross-section classification limits for elliptical hollow sections, developed on the basis of laboratory tests and numerical simulations. Four classes of cross-sections, namely Class 1 to 4 have been defined with limiting slenderness values. For the special case of elliptical hollow sections with an aspect ratio of unity, consistency with the slenderness limits for circular hollow sections in Eurocode 3 has been achieved. The proposed system of cross-section classification underpins the development of further design guidance for elliptical hollow sections.

• Steel and Composite Structures
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• v.7 no.4
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• pp.321-337
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• 2007

The investigation on the behaviour of cold-formed stainless steel non-slender circular hollow section columns is presented in this paper. The normal strength austenitic stainless steel type 304 and the high strength duplex materials (austenitic-ferritic approximately equivalent to EN 1.4462 and UNS S31803) were considered in this study. The finite element method has been used to carry out the investigation. The columns were compressed between fixed ends at different column lengths. The geometric and material nonlinearities have been included in the finite element analysis. The column strengths and failure modes were predicted. An extensive parametric study was carried out to study the effects of normal and high strength materials on cold-formed stainless steel non-slender circular hollow section columns. The column strengths predicted from the finite element analysis were compared with the design strengths calculated using the American Specification, Australian/New Zealand Standard and European Code for cold-formed stainless steel structures. The numerical results showed that the design rules specified in the American, Australian/New Zealand and European specifications are generally unconservative for the cold-formed stainless steel non-slender circular hollow section columns of normal and high strength materials, except for the short columns and some of the high strength stainless steel columns. Therefore, different values of the imperfection factor and limiting slenderness in the European Code design rules were proposed for cold-formed stainless steel non-slender circular hollow section columns.

• Steel and Composite Structures
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• v.6 no.4
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• pp.285-302
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• 2006

This paper describes the design and behaviour of cold-formed stainless steel slender circular hollow section columns. The columns were compressed between fixed ends at different column lengths. The investigation focused on large diameter-to-plate thickness (D/t) ratio ranged from 100 to 200. An accurate finite element model has been developed. The initial local and overall geometric imperfections have been included in the finite element model. The material nonlinearity of the cold-formed stainless steel sections was incorporated in the model. The column strengths, load-shortening curves as well as failure modes were predicted using the finite element model. The nonlinear finite element model was verified against test results. An extensive parametric study was carried out to study the effects of cross-section geometries on the strength and behaviour of stainless steel slender circular hollow section columns with large D/t ratio. The column strengths predicted from the parametric study were compared with the design strengths calculated using the American Specification, Australian/New Zealand Standard and European Code for cold-formed stainless steel structures. It is shown that the design strengths obtained using the Australian/New Zealand and European specifications are generally unconservative for the cold-formed stainless steel slender circular hollow section columns, while the American Specification is generally quite conservative. Therefore, design equation was proposed in this study.

• Steel and Composite Structures
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• v.19 no.3
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• pp.585-599
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• 2015

This paper presents the experimental work on fatigue life and specific fatigue strength of circular hollow sectioned steel tube and wood filled circular hollow section steel tube. Burning effect was observed in the case of circular hollow sectioned steel tube when it is subjected to Maximum bending moment of 19613.30 N-mm at 4200 rpm, but this did not happen in the case of wood filled hollow section. Statistical analysis was done based on the experimental data and relations have been built to predict the number of cycles for the applied stress or vice versa. The relations built in this paper can safely be applied for design of the fatigue life or fatigue strength of circular hollow sections and wood filled hollow sections. Results were validated by static specific bending strengths determined by ANSYS using a known applied load.

• Journal of Korean Association for Spatial Structures
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• v.13 no.4
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• pp.75-81
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• 2013

The circular hollow section is usually used for member of main frame to carry the external load in single layer lattice dome. But, the H-shaped section may be used for member of main frame since it is convenient for attaching roof panels. Single layer lattice domes have various buckling characteristics, such as the overall buckling, the member buckling, and nodal buckling. The purpose of this study is to compare buckling characteristics of single-layer lattice domes in which the H-shaped steel section as the existing domestically-produced structural steel is used as main frames to those of domes in which a circular hollow section is used as main frames.

• Steel and Composite Structures
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• v.3 no.2
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• pp.75-95
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• 2003

A numerical model is presented to simulate the mechanical behaviour of composite steel and concrete columns taking into account the interaction between the hollow steel section and the concrete core. The model, based on displacement finite element methods with an Updated Lagrangian formulation, allows for geometrical and material non linearities combined with heating over all or a part of the section and column length. Comparisons of numerical calculations made using the model with 33 fire resistance tests show that the model is able to predict the fire resistance, expressed in minutes of fire exposure, of composite columns with a good accuracy.

• Journal of the Earthquake Engineering Society of Korea
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• v.25 no.5
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• pp.191-199
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• 2021

In seismic design, hollow section concrete columns offer advantages by reducing the weight and seismic mass compared to concrete section RC bridge columns. However, the flexure-shear behavior and spirals strain of hollow section concrete columns are not well-understood. Octagonal RC bridge columns of a small-scale model were tested under cyclic lateral load with constant axial load. The volumetric ratio of the transverse spiral hoop of all specimens is 0.00206. The test results showed that the structural performance of the hollow specimen, such as the initial crack pattern, initial stiffness, and diagonal crack pattern, was comparable to that of the solid specimen. However, the lateral strength and ultimate displacement of the hollow specimen noticeably decreased after the drift ratio of 3%. The columns showed flexure-shear failure at the final stage. Analytical and experimental investigations are presented in this study to understand a correlation confinement steel ratio with neutral axis and a correlation between the strain of spirals and the shear resistance capacity of steel in hollow and solid section concrete columns. Furthermore, shear strength components (V_c, V_s·, V_p) and concrete stress were investigated.

• Journal of Korean Society of Steel Construction
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• v.17 no.1 s.74
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• pp.73-82
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• 2005

The objective of this study is to investigate the maximum strength of stainless steel rectangular hollow section columns and beam-columns by using numerical analysis. Stress-strain relationships are modeled based on coupon tests results, and their influences on the maximum strength of columns and beam-columns are discussed. The analysis results are compared with the formula for the limit state design code of steel structures. It is ascertained that the design code for the stainless steel is needed to use stainless steel for the members of architectural structures.

• Structural Engineering and Mechanics
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• v.23 no.5
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• pp.563-577
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• 2006

This study involves a series of experiments on the buckling strength of eccentrically compressed cold-formed stainless steel square hollow-section columns. The principal parameters in this study are slenderness ratios ($L_k/r$ = 30, 50, 70) and magnitude of eccentricity e (0, 25, 50, 75, 100 mm) on the symmetrical end-moment. The objectives of this paper are to obtain the buckling loads by conducting a series of experiments and to compare the behavior of the eccentrically compressed cold-formed stainless steel square hollow-section columns with the results of the analysis. The ultimate buckling strength of the square-section members were determined with the use of a numerical method in accordance with the bending moment-axial force (M-P) interaction curves. The behavior of each specimen was displayed in the form of a moment-radian (M-${\theta}$) relationship. The numerically obtained ultimate-buckling interaction curves of the beam columns coincided with the results of the experiments.

• Structural Engineering and Mechanics
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• v.74 no.1
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• pp.145-156
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• 2020

There are separate merits and demerits to wood and steel. The combination of wood and steel as a compound section is able to improve the properties of both and ultimately increase their final bearing capacity. The composite cross-section made of steel and wood has higher hardness while showing more ductility and the local buckling of steel is delayed or completely prevented. The purpose of this study is to investigate the behavior of composite columns enclosed in wooden logs and the hollow sections of steel that will be examined in a laboratory environment under the axial load to determine the final bearing capacity and sample deformation. In terms of methodology, steel sheet and carbon fiber reinforced polymer sheet (FRP) are tested to construct hollow rectangular sections and reinforce timber. Besides, the method of connecting hollow sections and timber including glue and screw has been also investigated. As a result, timber lumber enclosed with carbon fiber-reinforced polymer sheets in which fibers are horizontally located at 90° are more resistant with better ductility.