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Analytical model for the composite effect of coupled beams with discrete shear connectors

  • Zheng, Tianxin;Lu, Yong;Usmani, Asif
    • Structural Engineering and Mechanics
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    • v.52 no.2
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    • pp.369-389
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    • 2014
  • Two-layer coupled or composite beams with discrete shear connectors of finite dimensions are commonly encountered in pre-fabricated construction. This paper presents the development of simplified closed-form solutions for such type of coupled beams for practical applications. A new coupled beam element is proposed to represent the unconnected segments in the beam. General solutions are then developed by an inductive method based on the results from the finite element analysis. A modification is subsequently considered to account for the effect of local deformations. For typical cases where the local deformation is primarily concerned about its distribution over the depth of the coupled beam, empirical modification factors are developed based on parametric calculations using finite element models. The developed analytical method for the coupled beams in question is simple, sufficiently accurate, and suitable for quick calculation in engineering practice.

Coupled hydroelastic vibrations of a liquid on flexible space structures under zero-gravity - Part I. Mechanical model

  • Chiba, Masakatsu;Chiba, Shinya;Takemura, Kousuke
    • Coupled systems mechanics
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    • v.2 no.4
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    • pp.303-327
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    • 2013
  • The coupled free vibration of flexible structures and on-board liquid in zero gravity space was analyzed, considering the spacecraft main body as a rigid mass, the flexible appendages as two elastic beams, and the on-board liquid as a "spring-mass" system. Using the Lagrangians of a rigid mass (spacecraft main body), "spring-mass" (liquid), and two beams (flexible appendages), as well as assuming symmetric motion of the system, we obtained the frequency equations of the coupled system by applying Rayleigh-Ritz method. Solving these frequency equations, which are governed by three system parameters, as an eigenvalue problem, we obtained the coupled natural frequencies and vibration modes. We define the parameter for evaluating the magnitudes of coupled motions of the added mass (liquid) and beam (appendages). It was found that when varying one system parameter, the frequency curves veer, vibration modes exchange, and the significant coupling occurs not in the region closest to the two frequency curves but in the two regions separate from that region.

A high precision direct integration scheme for non-stationary random seismic responses of non-classically damped structures

  • Lin, Jiahao;Shen, Weiping;Williams, F.W.
    • Structural Engineering and Mechanics
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    • v.3 no.3
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    • pp.215-228
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    • 1995
  • For non-classically damped structures subjected to evolutionary random seismic excitations, the non-stationary random responses are computed by means of a high precision direct (HPD) integration scheme combined with the pseudo excitation method. Only real modes are used, so that the reduced equations of motion remain coupled for such non-classically damped structures. In the given examples, the efficiency of this method is compared with that of the Newmark method.

Special Issue on computational methods in engineering (CILAMCE 2018 - Paris/Compiegne)

  • Ibrahimbegovic, Adnan;Pimenta, Paulo M.
    • Coupled systems mechanics
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    • v.8 no.2
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    • pp.95-98
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    • 2019
  • This special issue contains selected papers first presented in a short format at the Congress CILAMCE 2018 ($39^{th}$ Ibero-Latin American Congress on Computational Methods in Engineering) held in Paris and in $Compi{\grave{e}}gne$, France, from 11 to 14 November 2018.

Differential quadrature method for free vibration analysis of coupled shear walls

  • Bozdogan, K.B.
    • Structural Engineering and Mechanics
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    • v.41 no.1
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    • pp.67-81
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    • 2012
  • Differential Quadrature Method (DQM) is a powerful method which can be used to solve numerical problems in the analysis of structural and dynamical systems. In this study the governing equation which represents the free vibration of coupled shear walls is solved using the DQM method. A one-dimensional model has been used in this study. At the end of study various examples are presented to verify the accuracy of the method.

Combined multi-predict-correct iterative method for interaction between pulsatile flow and large deformation structure

  • Wang, Wenquan;Zhang, Li-Xiang;Yan, Yan;Guo, Yakun
    • Coupled systems mechanics
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    • v.1 no.4
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    • pp.361-379
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    • 2012
  • This paper presents a fully coupled three-dimensional solver for the analysis of interaction between pulsatile flow and large deformation structure. A partitioned time marching algorithm is employed for the solution of the time dependent coupled discretised problem, enabling the use of highly developed, robust and well-tested solvers for each field. Conservative transfer of information at the fluid-structure interface is combined with an effective multi-predict-correct iterative scheme to enable implicit coupling of the interacting fields at each time increment. The three-dimensional unsteady incompressible fluid is solved using a powerful implicit time stepping technique and an ALE formulation for moving boundaries with second-order time accurate is used. A full spectrum of total variational diminishing (TVD) schemes in unstructured grids is allowed implementation for the advection terms and finite element shape functions are used to evaluate the solution and its variation within mesh elements. A finite element dynamic analysis of the highly deformable structure is carried out with a numerical strategy combining the implicit Newmark time integration algorithm with a Newton-Raphson second-order optimisation method. The proposed model is used to predict the wave flow fields of a particular flow-induced vibrational phenomenon, and comparison of the numerical results with available experimental data validates the methodology and assesses its accuracy. Another test case about three-dimensional biomedical model with pulsatile inflow is presented to benchmark the algorithm and to demonstrate the potential applications of this method.

Closed-form and numerical solution of the static and dynamic analysis of coupled shear walls by the continuous method and the modified transfer matrix method

  • Mao C. Pinto
    • Structural Engineering and Mechanics
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    • v.86 no.1
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    • pp.49-68
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    • 2023
  • This study investigates the static and dynamic structural analysis of symmetrical and asymmetrical coupled shear walls using the continuous and modified transfer matrix methods by idealizing the coupled shear wall as a three-field CTB-type replacement beam. The coupled shear wall is modeled as a continuous structure consisting of the parallel coupling of a Timoshenko beam in tension (with axial extensibility in the shear walls) and a shear beam (replacing the beam coupling effect between the shear walls). The variational method using the Hamilton principle is used to obtain the coupled differential equations and the boundary conditions associated with the model. Using the continuous method, closed-form analytical solutions to the differential equation for the coupled shear wall with uniform properties along the height are derived and a numerical solution using the modified transfer matrix is proposed to overcome the difficulty of coupled shear walls with non-uniform properties along height. The computational advantage of the modified transfer matrix method compared to the classical method is shown. The results of the numerical examples and the parametric analysis show that the proposed analytical and numerical model and method is accurate, reliable and involves reduced processing time for generalized static and dynamic structural analysis of coupled shear walls at a preliminary stage and can used as a verification method in the final stage of the project.

Transient wave propagation in piezoelectric hollow spheres subjected to thermal shock and electric excitation

  • Dai, H.L.;Wang, X.
    • Structural Engineering and Mechanics
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    • v.19 no.4
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    • pp.441-457
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    • 2005
  • An analytical method is presented to solve the problem of transient wave propagation in a transversely isotropic piezoelectric hollow sphere subjected to thermal shock and electric excitation. Exact expressions for the transient responses of displacements, stresses, electric displacement and electric potentials in the piezoelectric hollow sphere are obtained by means of Hankel transform, Laplace transform, and inverse transforms. Using Hermite non-linear interpolation method solves Volterra integral equation of the second kind involved in the exact expression, which is caused by interaction between thermo-elastic field and thermo-electric field. Thus, an analytical solution for the problem of transient wave propagation in a transversely isotropic piezoelectric hollow sphere is obtained. Finally, some numerical results are carried out, and may be used as a reference to solve other transient coupled problems of thermo-electro-elasticity.