• Title/Summary/Keyword: analytical and numerical methods

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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.

Benchmark Numerical Simulation on the Coupled Behavior of the Ground around a Point Heat Source Using the TOUGH-FLAC Approach (TOUGH-FLAC 기법을 이용한 점열원 주변지반의 복합거동에 대한 벤치마크 수치모사)

  • Dohyun Park
    • Tunnel and Underground Space
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    • v.34 no.2
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    • pp.127-142
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    • 2024
  • The robustness of a numerical method means that its computational performance is maintained under various modeling conditions. New numerical methods or codes need to be assessed for robustness through benchmark testing. The TOUGH-FLAC modeling approach has been applied to various fields such as subsurface carbon dioxide storage, geological disposal of spent nuclear fuel, and geothermal development both domestically and internationally, and the modeling validity has been examined by comparing the results with experimental measurements and other numerical codes. In the present study, a benchmark test of the TOUGH-FLAC approach was performed based on a coupled thermal-hydro-mechanical behavior problem with an analytical solution. The analytical solution is related to the temperature, pore water pressure, and mechanical behavior of a fully saturated porous medium that is subjected to a point heat source. The robustness of the TOUGH-FLAC approach was evaluated by comparing the analytical solution with the results of numerical simulation. Additionally, the effects of thermal-hydro-mechanical coupling terms, fluid phase change, and timestep on the computation of coupled behavior were investigated.

Analysis Method of Passive Piles considering group effect (군말뚝효과를 고려한 수동말뚝의 해석기법)

  • 정상섬;원진오;김병철
    • Proceedings of the Korean Geotechical Society Conference
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    • 2000.03b
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    • pp.151-158
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    • 2000
  • The lateral deformation of one row pile groups was investigated based on analytical study and a numerical analysis. The emphasis was on quantifing the load transfer of pile groups subjected to lateral soil movement. An analytical method to consider pile-soil interaction in weathered soil was developed using load-transfer curve methods. Through the comparative study, it is found that the prediction by present approach is in good agreement with the general trend observed by in-situ measurements.

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Prediction of initiation time of corrosion in RC using meshless methods

  • Yao, Ling;Zhang, Lingling;Zhang, Ling;Li, Xiaolu
    • Computers and Concrete
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    • v.16 no.5
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    • pp.669-682
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    • 2015
  • Degradation of reinforced concrete (RC) structures due to chloride penetration followed by reinforcement corrosion has been a serious problem in civil engineering for many years. The numerical simulation methods at present are mainly finite element method (FEM) and finite difference method (FDM), which are based on mesh. Mesh generation in engineering takes a long time. In the present article, the numerical solution of chloride transport in concrete is analyzed using radial point interpolation method (RPIM) and element-free Galerkin (EFG). They are all meshless methods. RPIM utilizes radial polynomial basis, whereas EFG uses the moving least-square approximation. A Galerkin weak form on global is used to attain the discrete equation, and four different numerical examples are presented. MQ function and appropriate parameters have been proposed in RPIM. Numerical simulation results are compared with those obtained from the finite element method (FEM) and analytical solutions. Two case of chloride transport in full saturated and unsaturated concrete are analyzed to test the practical applicability and performance of the RPIM and EFG. A good agreement is obtained among RPIM, EFG, and the experimental data. It indicates that RPIM and EFG are reliable meshless methods for prediction of chloride concentration in concrete structures.

Analytical solutions for skewed thick plates subjected to transverse loading

  • Chun, Pang-Jo;Fu, Gongkang;Lim, Yun Mook
    • Structural Engineering and Mechanics
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    • v.38 no.5
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    • pp.549-571
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    • 2011
  • This paper presents analytical solutions for skewed thick plates under transverse loading that have previously been unreported in the literature. The thick plate solution is obtained in a framework of an oblique coordinate system. The governing equation is first derived in the oblique coordinate system, and the solution is obtained using deflection and rotation as partial derivatives of a potential function developed in this research. The solution technique is applied to three illustrative application examples, and the results are compared with numerical solutions in the literature and those derived from the commercial finite element analysis package ANSYS 11. These results are in excellent agreement. The present solution may also be used to model skewed structures such as skewed bridges, to facilitate efficient routine design or evaluation analyses, and to form special elements for finite element analysis. At the same time, the analytical solution developed in this research could be used to develop methods to address post-buckling and dynamic problems.

Analytical studies on stress concentration due to a rectangular small hole in thin plate under bending loads

  • Yang, Y.;Liu, J.K.;Cai, C.W.
    • Structural Engineering and Mechanics
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    • v.36 no.6
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    • pp.669-678
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    • 2010
  • In general means, the stress concentration problem of elastic plate with a rectangular hole can be investigated by numerical methods, and only approximative results are derived. This paper deduces an analytical study of the stress concentration due to a rectangular hole in an elastic plate under bending loads. Base on classical elasticity theory and FEM applying the U-transformation technique, the uncoupled governing equations with 3-DOF are established, and the analytical displacement solutions of the finite element equations are derived in series form or double integral form. Therefore, the stress concentration factor can then be discussed easily and conveniently. For the plate subjected to unidirectional bending loads, the non-conforming plate bending element with four nodes and 12-DOF is taken as examples to demonstrate the application of the proposed method. The inner force distribution is obtained. The solutions are adequate for the condition when the hole is far away from the edges and the thin plate subjected to any transverse loadings.

Analysis of a Composite Double Cantilever Beam with Stitched Reinforcements Under Mixed Mode Loading : Formulation (I)

  • Jang Insik;Sankar Bhavani V.
    • Journal of Mechanical Science and Technology
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    • v.19 no.2
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    • pp.567-577
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    • 2005
  • Several methods for improving the interlaminar strength and fracture toughness of composite materials are developed. Through-the-thickness stitching is considered one of the most common ways to prevent delamination. Stitching significantly increases the Mode I fracture toughness and moderately improves the Mode II fracture toughness. An analytical model has been developed for simulating the behavior of stitched double cantilever beam specimen under various loading conditions. For z-directional load and moment about the y-axis the numerical solutions are compared with the exact solutions. The derived formulation shows good accuracy when the relative error of displacement and rotation between numerical and exact solution were calculated. Thus we can use the present model with confidence in analyzing other problems involving stitched beams.

Development of Dual Mass Flywheel (이중질량플라이휠의 개발)

  • 지태한;정재훈;송영래
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2003.11a
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    • pp.1067-1072
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    • 2003
  • Generally dual mass flywheel(DMF) is used as a solution to reduce noise and vibration of power train system and to improve the comfortability of passenger car. In this paper, design concept of new DMF model, analytical/numerical model, test procedure and tuning results are presented. Design parameters are studied by some numerical methods and tests. As the result, we can find more efficient model of DMF and reduce vibration level in power train system.

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Nonlinear vibration of oscillatory systems using semi-analytical approach

  • Bayat, Mahmoud;Bayat, Mahdi;Pakar, Iman
    • Structural Engineering and Mechanics
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    • v.65 no.4
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    • pp.409-413
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    • 2018
  • In this paper, He's Variational Approach (VA) is used to solve high nonlinear vibration equations. The proposed approach leads us to high accurate solution compared with other numerical methods. It has been established that this method works very well for whole range of initial amplitudes. The method is sufficient for both linear and nonlinear engineering problems. The accuracy of this method is shown graphically and the results tabulated and results compared with numerical solutions.

Deflection of battened beams with shear and discrete effects

  • Li, Ji-liang;Chen, Jian-kang
    • Structural Engineering and Mechanics
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    • v.59 no.5
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    • pp.921-932
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    • 2016
  • This paper presents a theoretical analysis for determining the transverse deflection of simply supported battened beams subjected to a uniformly distributed transverse quasi-static load. The analysis considers not only the shear effect but also the discrete effect of battens on the transverse deflection of the battened beam. The analytical solution is obtained using the principle of minimum potential energy. Numerical validation of the present analytical solution is accomplished using finite element methods. The present analytical solution shows that the shear effect on the transverse deflection of battened beams increases with the cross-section area of the main member but decreases with the cross-section area of the batten. The longer the battened beam is, or the larger the moment of inertia of the main member is, the smaller the shear effect will be.