• International Journal of Precision Engineering and Manufacturing
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• 제4권1호
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• pp.15-22
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• 2003

Beams are often subject to bending-torsion coupled vibration due to mass coupling and/or stiffness coupling. This paper proposes a dynamic analysis method using the exact dynamic element for bending-torsion coupled vibration of general plane beam structures with joints. The exact dynamic element matrix for a bending-torsion coupled beam is derived, and the detailed procedure of using the exact dynamic element matrix is also presented. Three examples are provided for validating and illustrating the proposed method. The numerical study proves the proposed method to be useful for dynamic analysis of bending-torsion coupled beam structures with joints.

• Steel and Composite Structures
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• 제9권6호
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• pp.499-518
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• 2009

The present paper investigates the stochastic seismic responses of steel structure systems with Partially Restrained (PR) connections by using Perturbation based Stochastic Finite Element (PSFEM) method. A stiffness matrix formulation of steel systems with PR connections and PSFEM and MCS formulations of structural systems are given. Based on the formulations, a computer program in FORTRAN language has been developed, and stochastic seismic analyses of steel frame and bridge systems have been performed for different types of connections. The connection parameters, material and geometrical properties are assumed to be random variables in the analyses. The Kocaeli earthquake occurred in 1999 is considered as a ground motion. The connection parameters, material and geometrical properties are considered to be random variables. The efficiency and accuracy of the proposed SFEM algorithm are validated by comparison with results of Monte Carlo simulation (MCS) method.

• 한국공간구조학회:학술대회논문집
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• 한국공간구조학회 2005년도 춘계학술발표회 및 정기총회 2권1호(통권2호)
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• pp.154-160
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• 2005

The present study is concerned with the application of dynamic relaxation method in the investigation of the large deflection behavior of spatial structures. The dynamic relaxation do not require the computation or formulation of any tangent stiffness matrix. The convergence to the solution is achieved by using only vectorial quantities and no stiffness matrix is required in its overall assembled form. In an effort to evaluate the merits of the methods, extensive numerical studies were carried out on a number of selected structural systems. The advantages of using dynamic relaxation methods, in tracing the post-buckling behavior of spatial structures, are demonstrated.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 1997년도 춘계 학술발표회 논문집 Proceedings of EESK Conference-Fall 1997
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• pp.107-114
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• 1997

A dynamic fluid-structure-soil interaction analysis method is developed to investigate the effects of rocking motion on the seismic response of the 3-D flexible rectangular liquid storage tanks founded on the deformable ground. The governing equation of 3-D rectangular tanks subjected to the translational and rocking motions is obtained by Rayleigh-Ritz method. The dynamic stiffness matrix of the rigid surface foundation resting on the surface of a stratum are calculated by hyperelement method. The seismic responses of a 3-D flexible tank model founded on the deformable ground is calculated by combining the governing equation of the structural motion with the dynamic stiffness matrix of the rigid surface foundation.

• Structural Engineering and Mechanics
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• 제44권4호
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• pp.539-569
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• 2012

The behaviour of beam-to-column connections plays an important role in the analysis and design of steel structures. A computer-based method is presented for nonlinear steel frames with semi-rigid connections accounting for shear deformations. The analytical procedure employs transcendental stability functions to model the effect of axial force on the stiffness of members. The member stiffness matrix, and the fixed end forces for various loads were found. The nonlinear analysis method is applied for three planar steel structures. The method is readily implemented on a computer using matrix structural analysis techniques and is applicable for the efficient nonlinear analysis of frameworks.

• 소음진동
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• 제8권5호
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• pp.949-956
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• 1998

Complex and large lattice type structures are frequently used in design of bridge, tower, crane and aerospace structures. In general, in order to analyze these structures we have used the finite element method(FEM). This method is the most widely used and powerful method for structural analysis lately. However, it is necessary to use a large amount of computer memory and computational time because the FEM requires many degrees of freedom for solving dynamic problems exactly for these complex and large structures. For analyzing these structures on a personal computer, the authors developed the transfer stiffness coefficient method(TSCM). This method is based on the concept of the transfer of the nodal dynamic stiffness coefficient matrix which is related to force and displacement vector at each node. And we suggested TSCM for free vibration analysis of complex and large lattice type structures in the previous report. In this paper, we formulate forced vibration analysis algorithm for complex and large lattice type structures using extened TSCM. And we confirmed the validity of TSCM through computational results by the FEM and TSCM, and experimental results for lattice type structures with harmonic excitation.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1998년도 춘계학술대회논문집; 용평리조트 타워콘도, 21-22 May 1998
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• pp.426-431
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• 1998

This, paper describes formulation for time historical response analysis of vibration for tree structure. This method is derived from a combination of the transfer stiffness coefficient method and the Newmark-.betha. method. And This present method improves the computational accuracy of the transient vibration response analysis remarkably owing to several advantages of the transfer stiffness coefficient method. We regarded the structure as a lumped mass system here. The analysis algorithm for the time historical response was formulated for the tree structure. The validity of the present method compared with the transfer matrix method and the FEM(Finite Element Method) for transient vibration analysis is demonstrated through the numerical computations.

• 대한기계학회논문집
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• 제17권12호
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• pp.3007-3019
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• 1993

For the same configuration, the stiffness of 6-node two dimensional isoparametric is stiffer than that of 8-node two dimensional isoparametric element. This phenomenon may be called 'Relative Stiffness Stiffening Phenomenon.' In this paper, the relative stiffness stiffening phenomenon was studied, and could be corrected by modifying the position of Gauss integral points used in the numerical integration of the stiffness matrix. For the same deformation (bending) energy of 6-node and 8-node two dimensional isoparametric elements, Gauss integral points of 6-node element have to move closer, in comparison with those of 8-node element, in the case of numerical integration along the thickness direction.

• Structural Engineering and Mechanics
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• 제58권3호
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• pp.423-442
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• 2016

This study considers a functionally graded (FG) elastic layer resting on homogeneous elastic substrate under axisymmetric static loading. The shear modulus of the FG layer is assumed to vary in an exponential form through the thickness. In solution, the FG layer is approximated into a multilayered medium consisting of thin homogeneous sublayers. Stiffness matrices for a typical homogeneous isotropic elastic layer and a half-space are first obtained by solving the axisymmetric elasticity equations with the aid of Hankel's transform. Global stiffness matrix is, then, assembled by considering the continuity conditions at the interfaces. Numerical results for the displacements and the stresses are obtained and compared with those of the classical elasticity and the finite element solutions. According to the results of the study, the approach employed here is accurate and efficient for elasto-static problems of FGMs.

• 한국자동차공학회논문집
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• 제6권3호
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• pp.54-62
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• 1998

In this study, collapse behavior of frame composed of thin-walled rectangular tube is investigated. Considering the collapse of frame, the bending and compression members undergo large deformation. The stiffness of the compound element is obtained from analytical moment-rotation relationship and approximated load-deflection relationsh- ip of thin-walled rectangular tube. A computer program is developed for the large deformation analysis of frame. An incremental displacement method is used in the program and at each incremental stage, the stiffness matrix of the total structure is checked with the state of each element for bending and compression.