Abstract
Steel beam-to-column joints are often subjected to a combination of bending and axial forces. The level of axial forces in the joint may be significant, typical of pitched-roof portal frames, sway frames or frames with incomplete floors. Current specifications for steel joints do not take into account the presence of axial forces (tension and/or compression) in the joints. A single empirical limitation of 10% of the beam
Key Words
component method; experimental analysis; flush end-plate joints; semi-rigid behaviour; bending and axial force.
Address
Luis Simoes da Silva; Civil Engineering Department, University of Coimbra, Polo II, Pinhal de Marrocos, 3030 Coimbra, PortugalrnLuciano R. O. de Lima and Pedro C. G. da S. Vellasco; Structural Engineering Department, UERJ - State University of Rio de Janeiro, BrazilrnSebastiao A. L. de Andrade; Civil Engineering Department, PUC-RIO - Pontifical Catholic University of Rio de Janeiro, Brazil
Abstract
A series of tests was performed to consider the behaviour of short composite columns under axial compressive loading, covering a range of S275 and S355 grade steel square hollow section filled with normal and high strength concrete. The interaction between the steel and the concrete component is considered and the results show that concrete shrinkage has an effect on the axial strength of the column. Comparisons between Eurocode 4, ACI-318 and the Australian Standards with the findings of this research were made. Result showed the equation used by the ACI-318 and the proposed Australian Standards gave better predication for the axial capacity of concrete filled SHS columns than the Eurocode 4.
Address
Dennis Lam; School of Civil Engineering, University of Leeds, Leeds, LS2 9JT, U.K.rnChristopher A. Williams; Arup, Admiral House, 78 East Street, Leeds, LS9 8EE, U.K.
Abstract
Double skin composite element (DSCE) is a novel form of construction comprising two skins of profiled steel sheeting with an infill of concrete. DSCEs are thought to be applicable as shear or core walls in a building where they can resist in-plane loads. In this paper, the behaviour of DSCE subjected to combined bending and shear deformation is described. Small-scale model tests on DSCEs manufactured from microconcrete and very thin sheeting were conducted to investigate the flexural and shear behaviour along with analytical analysis. The model tests provided information on the strength, stiffness, strain conditions and failure modes of DSCEs. Detailed development of analytical models for strength and stiffness and their performance validation by model tests are presented.rn
Key Words
double skin composite element; bending and shear strength, profiled steel sheeting; sheetconcrete interaction; analytical models.
Address
K. M. Anwar Hossain; Department of Civil Engineering, Ryerson University, Toronto, CanadarnH. D. Wright; Department of Civil Engineering, University of Strathclyde, Glasgow, UK
Abstract
This paper deals with the asymptotic analysis of Mohr-Coulomb and Drucker-Prager soft thin layers bonded with elastic solids. In the first part, a mathematical analysis shows how to obtain an interface law that replaces mechanically and geometrically the thin layer. This law is strongly non-linear and couples microscopic and macroscopic scales. In the second part of the paper, the microscopic terms are quantified numerically, and it is shown that they can be neglected.
Address
F. Lebon and S. Ronel-Idrissi; Laboratoire Mecanique Matriaux Structures, Universita Claude Bernard Lyon 1, 82 Bd Niels Bohr, Domaine Scientifique de la Doua, 69622 Villeurbanne Cedex, France
Abstract
Offshore platforms have to serve in harsh environments and hence are likely to be damaged due to wave induced fatigue and environmental corrosion. Welded tubular joints in offshore platforms are most vulnerable to fatigue damage. Such damages endanger the integrity of the structure. Therefore it is all the more essential to assess the capacity of damaged structure from the point of view of its safety. Eight internally ring stiffened fatigue damaged tubular joints with nominal chord and brace diameter of 324 mm and 219 mm respectively and thickness 12 mm and 8 mm respectively were tested under axial brace compression loading to evaluate the reserve capacity of the joints. These joints had earlier been tested under fatigue loading under corrosive environments of synthetic sea water and hence they have been cracked. The extent of the damage varied from 35 to 50 per cent. One stiffened joint was also tested under axial brace tension loading. The residual strength of fatigue damaged stiffened joint tested under tension loading was observed to be less than one fourth of that tested under compression loading. It was observed in this experimental investigation that in the damaged condition, the joints possessed an in-built load-transfer mechanism. A bi-linear stress-strain model was developed in this investigation to predict the reserve capacity of the joint. This model considered the strain hardening effect. Close agreement was observed between the experimental and predicted results. The paper presents in detail the experimental investigation and the development of the analytical model to predict the reserve capacity of internally ring stiffened joints.
Key Words
offshore platforms; internally ring stiffened joins; cracked; reserve capacity; experimental; analytical; bi-linear constitutive model.
Address
Shock and Vibration Laboratory, Structural Engineering Research Centre,rnCSIR Campus, Taramani, Chennai 600 113, Tamil Nadu, India
