Abstract
A new beam system comprising two cantilever stems and an interspan composite beam has been developed and its design philosophy is described in this paper. The system provides the equivalent of a semi-continuous beam without the requirement to calculate the moment rotation capacity of the beam-to-column connection. The economy of braced frames using the system has been investigated and compared with simple, continuous or semi-rigid systems. It is shown that the costs of the proposed system are similar to the semi-rigid system and cheaper than both the simply supported and rigid beam systems. Two tests have been carried out on 6 meter span beams, which also incorporated an asymmetric flange steel section. The behaviour of the system is presented and the test results are compared with those obtained from the theory.
Key Words
continuous stem girder system (csgs); asymmetric steel section beam (asb); economy of braced frames; semi-rigid connection.
Address
Boksun Kim, Scott Sutherland School of Architecture, Robert Gordon University, Garthdee Road, Aberdeen AB10 7QB, UK Howard D Wright and Roy Cairns, Department of Civil Engineering, University of Strathclyde, 107 Rottenrow, Glasgow G4 0NG, UK
Abstract
Modern soft computing methods, such as neural networks, evolutionary models and fuzzy logic, are mainly inspired by the problem solving strategies the biological systems use in nature. As such, the soft computing methods are fundamentally different from the conventional engineering problem solving methods, which are based on mathematics. In the author
Address
Jamshid Ghaboussi, Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, U.S.A.
Abstract
In this paper, the procedure for deriving an infinite element that is compatible with the quadrilateral Q8 element is first summarized. Enhanced by a self mesh-expansion procedure for generating the impedance matrices of different frequencies for the region extending to infinity, the infinite element is used to simulate the far field of the soil-structure system. The structure considered here is of the box type and the soils are either homogeneous or resting on a bedrock. Using the finite/infinite element approach, a parametric study is conducted to investigate the effect of open and in-filled trenches in reducing the structural vibration caused by a train passing nearby, which is simulated as a harmonic line load. The key parameters that dominate the performance of wave barriers in reducing the structural vibrations are identified. The results presented herein serve as a useful guideline for the design of open and in-filled trenches concerning wave reduction.
Key Words
finite/infinite element method; in-filled trench; infinite element; open trench; traffic-induced vibration; wave barrier.
Address
Hsiao-Hui Hung, Jenny Kuo and Yeong-Bin Yang, Department of Civil Engineering, National Taiwan University, Taipei, Taiwan, R.O.C.
Abstract
The effects of the initial imperfections on the nonlinear behaviors and ultimate strength of the thin-walled members subjected to the axial loads, obtained by the finite element stability analysis, are examined. As the initial imperfections, the buckling mode shapes of the members are adopted. The buckling mode shapes of the thin-walled members are obtained by the transfer matrix method. In the finite element stability analysis, isoparametric degenerated shell element is used, and the geometrical and material nonlinearity are considered based on the Green Lagrange strain definition and the Prandtl-Reuss stress-strain relation following the von Mises yield criterion. The U-, box- and I-section members subjected to the axial loads are adopted for numerical examples, and the effects of the initial imperfections on the nonlinear behaviors and ultimate strength of the members are examined.
Key Words
finite element stability analysis; initial imperfection; nonlinear behavior; thin-walled member; ultimate strength.
Address
M. Ohga, Department of Civil and Environmental Engineering, Ehime University, Matsuyama 790-8577, Japan A. Takaue, Chodai Ltd., Takamatsu 760-0017, Japan T. Shi gematsu and T. Hara, Tokuyama Technical College, Tokuyama 745-8585, Japan
Abstract
A new p-adaptive analysis scheme for hp-clouds method is presented. In the scheme, refined global equations are resolved into two parts, one of them being related to the newly appended dof
Abstract
The numerical formulation of a two-phase interface element appropriate for porous lining system is presented. The formulation is isoparametric and can be applied both for 2-D and 3-D analysis. Biot
Address
X. Liu, A. Scarpas and J. Blaauwendraad, Department of Civil Engineering and Geosciences, Delft University of Technology, Stevinweg 1, 2628CN Delft, The Netherlands
Abstract
Experimental investigation into the behaviour of half-scale brick masonry panels were conducted under cyclic loading normal to the bed joint and parallel to the bed joint. For each cycle, full reloading was performed with the cycle peaks coinciding approximately with the envelope curve. Unloading, however, was carried out fully to zero stress level and partially to two different stress levels of 25 percent and 50 percent of peak stress. Stability point limit exhibits a unique stress-strain curve for full unloading but it could not be established for partial unloading. Common point limit was established for all unloading-reloading patterns considered, but its location depends on the stress level at which unloading is carried to. Common point curves were found to follow an exponential formula, while residual strains versus envelope strains can be expressed by a polynomial function of a single term. The relation between residual strain and envelope strain can be used to determine the stress level at which deterioration due to cyclic loading began.
Key Words
partial unloading; reloading; residual strain; common point; stability point.
Address
Milad M. AlShebani, Department of Civil Engineering, AlFateh University, Tripoli, Libya S.N. Sinha, Department of Civil Engineering, Indian Institute of Technology, Hauz Khas, New Delhi-110 016, India
