Steel Square Hollow Section Research Articles

An experimental study and calculation on the fire resistance of concrete-filled SHS and RHS columns

Abstract The behavior of concrete-filled steel square hollow section (SHS) and rectangular hollow section (RHS) columns with or without fire protection subjected to axial or eccentric loads has been experimentally investigated and the results are presented in this paper. The parametric and experimental studies provide information for the development of formulas for the calculation of the fire resistance and the fire protection thickness of the composite columns. The main objectives of this paper were threefold: first, to report a series of fire tests on composite columns with square and rectangular sections. Secondly, to analyze the influence of several parameters, such as fire duration time, sectional dimension, slenderness ratio, load eccentricity ratio, strength of steel and concrete on the residual strength index (RSI) of the composite columns. Finally, to develop formulas for the calculation of the fire resistance and the fire protection thickness of the concrete-filled steel SHS and RHS columns, such formulas to be suitable for incorporation into building codes. The concepts of this paper were used to provide data on the necessary fire protection measures for the concrete-filled steel SHS columns used in a high-rise building, Ruifeng, Shangye Building in Hangzhou City, in southern China.

Buckling of stainless steel square hollow section compression members

Abstract This article describes a test program on cold-formed stainless steel square hollow section (SHS) subjected to pure axial compression. A series of tests was compressed between fixed ends. The specimens were cold-rolled from stainless steel sheets. The tests were performed over a range of column lengths, which involved local buckling and overall flexural buckling. Measurements of overall geometric imperfections and material properties of the specimens were conducted. The experimental column strengths were compared with the design strengths predicted by the American, Australian/New Zealand and European specifications for cold-formed stainless steel structures. Generally, the three specifications conservatively predict the strengths of the tested fixed-ended cold-formed stainless steel SHS columns. However, the design rules in the Australian/New Zealand Standard are slightly more reliable than the design rules in the American and European specifications.

Development of a fracture mechanics based analysis program for offshore structures: Dharmavasan, S., Kam, J.C.P., Hall, M.S. and Kare, R. Conf. Fatigue and Fracture in Steel and Concrete Structures, ISFF '91, Madras, India, Dec 1991 Vol 1 (Oxford & IBH Publishing Co. Pvt. Ltd, New Delhi, India, 1991) 285–295

An experimental programme was conducted to investigate the compressive behaviour of concrete-filled cold-formed steel tubular (CFCFST) stub columns with thicker tubes. A total of 30 CFCFST stub columns were tested. The cold-formed square hollow section (SHS) tubes included unstiffened sections and longitudinally inner-stiffened sections using different stiffening methods. Two tubular thicknesses of 6 mm and 10 mm were considered. The overall nominal dimension of the steel section was 200 × 200 mm, and the length of the stub columns was 600 mm. Normal concrete and self-consolidating concrete with a nominal compressive strength of 30 MPa were used to fill the cold-formed SHS steel tubes. The effects of the stiffeners on the rigidity, ductility, failure mode and average sectional strength of the CFCFST specimens were examined. The measured strengths of the CFCFST specimens were also compared with the predicted capacities using methods in various codes including AISC, BS5400, EC4, and DBJ and from a finite element (FE) analysis. Results demonstrate that the inner stiffeners affect the deformability, failure mode and overall strength of the stub columns with the 6 mm-thick tubes more significantly. The DBJ code method is comparatively the best in predicting the strength capacity. Using the validated FE model, an extended analysis has been conducted and this has provided further insight into the mechanical behaviour of the CFCFST specimens.

Remote sensing of fatigue crack propagation in CT specimens via strain measurement: Simha, K.R.Y., Ramakrishna, D.S. and Arora, P.R. Conf. Fatigue and Fracture in Steel and Concrete Structures, ISFF '91, Madras, India, Dec, 1991 Vol 1 (Oxford & IBH Publishing Co. Pvt. Ltd, New Delhi, India, 1991) 253–257

An experimental programme was conducted to investigate the compressive behaviour of concrete-filled cold-formed steel tubular (CFCFST) stub columns with thicker tubes. A total of 30 CFCFST stub columns were tested. The cold-formed square hollow section (SHS) tubes included unstiffened sections and longitudinally inner-stiffened sections using different stiffening methods. Two tubular thicknesses of 6 mm and 10 mm were considered. The overall nominal dimension of the steel section was 200 × 200 mm, and the length of the stub columns was 600 mm. Normal concrete and self-consolidating concrete with a nominal compressive strength of 30 MPa were used to fill the cold-formed SHS steel tubes. The effects of the stiffeners on the rigidity, ductility, failure mode and average sectional strength of the CFCFST specimens were examined. The measured strengths of the CFCFST specimens were also compared with the predicted capacities using methods in various codes including AISC, BS5400, EC4, and DBJ and from a finite element (FE) analysis. Results demonstrate that the inner stiffeners affect the deformability, failure mode and overall strength of the stub columns with the 6 mm-thick tubes more significantly. The DBJ code method is comparatively the best in predicting the strength capacity. Using the validated FE model, an extended analysis has been conducted and this has provided further insight into the mechanical behaviour of the CFCFST specimens.