• 제목/요약/키워드: techno

검색결과 18,759건 처리시간 0.034초

Optimal design of laminated composite plates to maximise fundamental frequency using MFD method

  • Topal, Umut;Uzman, Umit
    • Structural Engineering and Mechanics
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    • 제24권4호
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    • pp.479-491
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    • 2006
  • This paper deals with optimal fibre orientations of symmetrically laminated fibre reinforced composite structures for maximising the fundamental frequency of small-amplitude. A set of fiber orientation angles in the layers are considered as design variable. The Modified Feasible Direction method is used in order to obtain the optimal designs. The effects of number of layers, boundary conditions, laminate thicknesses, aspect ratios and in-plane loads on the optimal designs are studied.

Analytical modeling of thin-walled box T-joints

  • Marur, Prabhakar R.
    • Structural Engineering and Mechanics
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    • 제32권3호
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    • pp.447-457
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    • 2009
  • A general analytical method for computing the joint stiffness from the sectional properties of the members that form the joint is derived using Vlasov's thin-walled beam theory. The analytical model of box T-joint under out-of-plane loading is investigated and validated using shell finite element results and experimental data. The analytical model of the T-joint is implemented in a beam finite element model using a revolute joint element. The out-of-plane displacement computed using the beam-joint model is compared with the corresponding shell element model. The results show close correlation between the beam revolute joint model and shell element model.

Wind induced response of an elevated steel water tank

  • Sepe, Vincenzo;Zingali, Antonino E.
    • Wind and Structures
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    • 제4권5호
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    • pp.383-398
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    • 2001
  • The paper describes the results of the monitoring of an elevated steel water-tank with unusual shape, 85 m high and 40 m wide. The research was carried out analysing both the static and dynamic behaviour under wind actions. The instruments used (some of which were employed for the first time for this project) are described and the data processing procedures are discussed. Comparison between the experimental results and those obtained through a numerical model gives interesting information both on the structural behaviour and on the characterisation of wind actions.

Theoretical analysis of composite beams under uniformly distributed load

  • Daouadji, Tahar Hassaine;Adim, Belkacem
    • Advances in materials Research
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    • 제5권1호
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    • pp.1-9
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    • 2016
  • The bending problem of a functionally graded cantilever beam subjected to uniformly distributed load is investigated. The material properties of the functionally graded beam are assumed to vary continuously through the thickness, according to a power-law distribution of the volume fraction of the constituents. First, the partial differential equation, which is satisfied by the stress functions for the axisymmetric deformation problem is derived. Then, stress functions are obtained by proper manipulation. A practical example is presented to show the application of the method.

Influence of impulsive line source and non-homogeneity on the propagation of SH-wave in an isotropic medium

  • Kakar, Rajneesh
    • Interaction and multiscale mechanics
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    • 제6권3호
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    • pp.287-300
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    • 2013
  • In this paper, the effect of impulsive line on the propagation of shear waves in non-homogeneous elastic layer is investigated. The rigidity and density in the intermediate layer is assumed to vary quadratic as functions of depth. The dispersion equation is obtained by using the Fourier transform and Green's function technique. The study ends with the mathematical calculations for transmitted wave in the layer. These equations are in complete agreement with the classical results when the non-homogeneity parameters are neglected. Various curves are plotted to show the effects of non-homogeneities on shear waves in the intermediate layer.

Structural optimization with teaching-learning-based optimization algorithm

  • Dede, Tayfun;Ayvaz, Yusuf
    • Structural Engineering and Mechanics
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    • 제47권4호
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    • pp.495-511
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    • 2013
  • In this paper, a new efficient optimization algorithm called Teaching-Learning-Based Optimization (TLBO) is used for the least weight design of trusses with continuous design variables. The TLBO algorithm is based on the effect of the influence of a teacher on the output of learners in a class. Several truss structures are analyzed to show the efficiency of the TLBO algorithm and the results are compared with those reported in the literature. It is concluded that the TLBO algorithm presented in this study can be effectively used in the weight minimization of truss structures.

Behavior of lightweight aggregate concrete-encased composite columns

  • Al-Shahari, Abbas M.;Hunaiti, Yasser M.;Ghazaleh, Bassam Abu
    • Steel and Composite Structures
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    • 제3권2호
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    • pp.97-110
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    • 2003
  • An experimental study was conducted to investigate the behavior of eccentric lightweight aggregate concrete-encased composite columns. This study aims at verifying the validity of such type of concrete in composite construction and checking the adequacy of the AISC-LRFD and the British Bridge Code BS 5400 specifications in predicting the column strength. Sixteen full-scale pin ended columns subjected to uniaxial bending about the major axis in symmetrical single curvature were tested.

Influence of SMAs on the attenuation of effects of P-Δ type in shear frames

  • Corbi, Ottavia
    • Steel and Composite Structures
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    • 제3권6호
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    • pp.403-420
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    • 2003
  • In the paper one investigates the benefits deriving from the introduction of SMA provisions in a structure subject to dynamic excitation and vertical loads. At this purpose one considers a multi-degree-of-freedom (mdof) shear elastic-plastic frame and designs couples of super-elastic SMA tendons to be placed at critical locations of the structure. Particular attention is focused on the reduction of $P-{\Delta}$ effects.

Buckling and vibration of symmetric laminated composite plates with edges elastically restrained

  • Ashour, Ahmed S.
    • Steel and Composite Structures
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    • 제3권6호
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    • pp.439-450
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    • 2003
  • The finite strip transition matrix technique, a semi analytical method, is employed to obtain the buckling loads and the natural frequencies of symmetric cross-ply laminated composite plates with edges elastically restrained against both translation and rotation. To illustrate the accuracy and the validation of the method several example of cross play laminated composite plates were analyzed. The buckling loads and the frequency parameters are presented and compared with available results in the literature. The convergence study and the excellent agreement with known results show the reliability of the purposed technique.

Reduction of residual stress for welded joint using vibrational load

  • Aoki, Shigeru;Nishimura, Tadashi;Hiroi, Tetsumaro
    • Steel and Composite Structures
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    • 제4권5호
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    • pp.355-365
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    • 2004
  • A new reduction method of residual stress in welding joint is proposed where welded metals are shaken during welding. By an experiment using a small shaker, it can be shown that tensile residual stress near the bead is significantly reduced. Since tensile residual stress on the surface degrades fatigue strength for cumulative damage, the proposed method is effective to reduction of residual stress of welded joints. The effectiveness of the proposed method is demonstrated by the response analysis using one mass model with nonlinear springs.