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Influence of aspect ratio and fibre orientation on the stability of simply supported orthotropic skew plates

  • Kutlu, Darilmaz
    • Steel and Composite Structures
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    • v.11 no.5
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    • pp.359-374
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    • 2011
  • In this paper, the influence of fibre orientation and aspect ratio on stability analysis of simply supported skew plates subjected to in plane loading is studied by using a four noded hybrid plate finite element. The formulation of the element is based on Hellinger-Reissner variational principle. The element is developed by combining a hybrid plane stress element and a hybrid plate element. Some numerical problems are solved and the effects of skew angle, aspect ratio, fibre orientation and loading type on the critical buckling loads are highlighted.

Toward a paradigm for civil structural control

  • Casciati, S.;Chassiakos, A.G.;Masri, S.F.
    • Smart Structures and Systems
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    • v.14 no.5
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    • pp.981-1004
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    • 2014
  • Structural control is a very broad field combining the areas of automatic control and structural engineering, with applications ranging from aerospace and mechanical engineering to building and civil infrastructure systems. In this paper, the focus is placed on civil engineering applications only. The goal is to address the issues concurring to form the scientific paradigm. As a resut, possible future directions of research into this field are identified.

Detecting artefacts in analyses of extreme wind speeds

  • Cook, Nicholas J.
    • Wind and Structures
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    • v.19 no.3
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    • pp.271-294
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    • 2014
  • The impact of artefacts in archived wind observations on the design wind speed obtained by extreme value analysis is demonstrated using case studies. A signpost protocol for detecting candidate artefacts is described and its performance assessed by comparing results against previously validated data. The protocol targets artefacts by exploiting the serial correlation between observations. Additional "sieve" algorithms are proposed to identify types of correctable artefact from their "signature" in the data. In extreme value analysis, artefacts displace valid observations only when they are larger, hence always increase the design wind speed. Care must be taken not identify large valid values as artefacts, since their removal will tend to underestimate the design wind speed.

Free vibration of tapered arches made of axially functionally graded materials

  • Rajasekaran, S.
    • Structural Engineering and Mechanics
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    • v.45 no.4
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    • pp.569-594
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    • 2013
  • The free vibration of axially functionally graded tapered arches including shear deformation and rotatory inertia are studied through solving the governing differential equation of motion. Numerical results are presented for circular, parabolic, catenary, elliptic and sinusoidal arches with hinged-hinged, hinged-clamped and clamped-clamped end restraints. In this study Differential Quadrature element of lowest order (DQEL) or Lagrangian Interpolation technique is applied to solve the problems. Three general taper types for rectangular section are considered. The lowest four natural frequencies are calculated and compared with the published results.

Study on durability of densified high-performance lightweight aggregate concrete

  • Wang, H.Y.
    • Computers and Concrete
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    • v.4 no.6
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    • pp.499-510
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    • 2007
  • The densified mixture design algorithm (DMDA) was employed to manufacture high-performance lightweight concrete (LWAC) using silt dredged from reservoirs in southern Taiwan. Dredged silt undergoing hydration and high-temperature sintering was made into a lightweight aggregate for concrete mixing. The workability and durability of the resulting concrete were examined. The LWAC made from dredged silt had high flowability, which implies good workability. Additionally, the LWAC also had good compressive strength and anti-corrosion properties, high surface electrical resistivity and ultrasonic pulse velocity as well as low chloride penetration, all of which are indicators of good durability.

Analytical solutions for density functionally gradient magneto-electro-elastic cantilever beams

  • Jian, Aimin;Ding, Haojiang
    • Smart Structures and Systems
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    • v.3 no.2
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    • pp.173-188
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    • 2007
  • The general solution for two-dimensional magneto-electro-elastic media in terms of four harmonic displacement functions is proposed analytically. The expressions of specific solutions of magneto-electro-elastic plane problems with specific body forces are derived. Finally, based on the general solution in the case of distinct eigenvalues and the specific solution for density functionally gradient media, two kinds of beam problems with body forces depending only on the z or x coordinate are solved by the trial-and-error method.

Ground strain estimation for lifeline earthquake engineering

  • Koike, Takeshi;Maruyama, Osamu;Garciano, Lessandro Estelito
    • Structural Engineering and Mechanics
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    • v.25 no.3
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    • pp.291-310
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    • 2007
  • Current seismic design guidelines in Japan are diverse in the seismic ground strain estimates, because the concepts on a horizontally propagating wave model are not consistent in various seismic design guidelines including gas, water and other underground structures. The purpose of this study is (a) to derive the analytical methods to estimate the ground strains for incident seismic waves, (b) to develop a statistical estimation technique of the ground strains, and finally (c) to compare the theoretical estimation with the observed data which was measured at 441 sites in the 1999 Chi-Chi Earthquake in Taiwan.

Effectiveness of classical rolling pendulum bearings

  • Raftoyiannis, Ioannis G.;Michaltsos, George T.
    • Coupled systems mechanics
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    • v.6 no.2
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    • pp.127-139
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    • 2017
  • During the last decades, Pendulum Bearings with one or more concave sliding surfaces have been dominating bridge structures. For bridges with relative small lengths, the use of classical pendulum bearings could be a simple and cheaper solution. This work attempts to investigate the effectiveness of such a system, and especially its behavior for the case of a seismic excitation. The results obtained have shown that the classical pendulum bearings are very effective, mainly for bridges with short or intermediate length.

Setting the scene: CFD and symposium overview

  • Murakami, Shuzo
    • Wind and Structures
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    • v.5 no.2_3_4
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    • pp.83-88
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    • 2002
  • The present situation of CWE(Computational Wind Engineering) and the papers presented to the CWE 2000 Symposium are reviewed from the following viewpoints; 1) topics treated, 2) utilization of commercial code (software), 3) incompleteness of CWE, 4) remaining research subjects, 5) prediction accuracy, 6) new fields of CWE application, etc. Firstly, new tendencies within CWE applications are indicated. Next, the over-attention being given to the application field and the lack of attention to fundamental problems, including prediction error analysis, are pointed out. Lastly, the future trends of CFD (Computational Fluid Dynamics) applications to wind engineering design are discussed.