• Geomechanics and Engineering
• /
• 제2권1호
• /
• pp.45-56
• /
• 2010

The current study presents a mathematical model and numerical method for free vibration of tapered piles embedded in two-parameter elastic foundations. The method of Discrete Singular Convolution (DSC) is used for numerical simulation. Bernoulli-Euler beam theory is considered. Various numerical applications demonstrate the validity and applicability of the proposed method for free vibration analysis. The results prove that the proposed method is quite easy to implement, accurate and highly efficient for free vibration analysis of tapered beam-columns embedded in Winkler- Pasternak elastic foundations.

• Structural Engineering and Mechanics
• /
• 제87권4호
• /
• pp.391-403
• /
• 2023

In this study, a new type of self-centering beam-column joint with tapered steel plate links is proposed. Firstly, mechanical property of the basic joint (with the prestressed steel strands only, to provide the self-centering ability) and the combined joint (with both the prestressed steel strands and tapered steel plate links, to provide self-centering and energy dissipation simultaneously) is theoretically analyzed. Then, three joints with different dimensions and combinations of tapered plate links are designed and tested through a series of quasi-static cyclic loading tests. Test results show that a nearly bilinear elastic moment-rotation relationship for the basic joint is obtained. With the addition of tapered steel plate links, typical flag-shape hysteretic curves are obtained, which indicates good self-centering and energy dissipating ability of the combined joint. By installing multiple tapered plate links, stiffness and bearing capacity of the beam-column joint can be enhanced. The theoretical moment-rotation relationships agree well with the test results. A simplified macro model of the proposed joint is developed using OpenSees, which simulates reasonably well its hysteretic behavior.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2002년도 추계학술대회논문초록집
• /
• pp.402.1-402
• /
• 2002

A linearly tapered beam immersed partially in other material is considered and is modelled as a linearly tapered Bernoulli-Euler beam fixed at the bottom with a concentrated mass at the top. Its governing equations is derived and its free vibration analysis is performed for various boundary conditions. And the rotatory inertia of the eccentric lumped tip mass is considered. (omitted)

• 소음진동
• /
• 제6권5호
• /
• pp.587-594
• /
• 1996

이 논문에서는 일정체적의 정다각형 단면을 갖는 보-기둥의 자유진동 및 좌굴하중을 지배하는 비분방정식을 유도하고 이를 수치해석하였다. 정다각형 단면의 단면깊이 변화식으로는 포물선식과 정현식을 채택하였고, 고정-고정, 회전-고정 및 회전-회전의 단부조건에 대하여 고유진동수 및 좌굴하중을 산출하였다. 수치해석의 결과로 무차원 고유진동수와 무차원변들 사이의 관계 및 무차원 좌굴하중과 단면비 사이의 관계를 그림에 나타내었다. 또한, 최강기둥의 단면비와 좌국하중을 산출 하였다.

• 전산구조공학
• /
• 제9권3호
• /
• pp.135-143
• /
• 1996

일정체적의 원형단면을 갖는 변단면 보-기둥의 자유진동 및 좌굴하중을 지배하는 미분방정식을 유도하고 이를 수치해석하였다. 미분방정식에는 축하중효과를 고려하였다. 원형단면의 반경변화는 포물선식을 채택하였고, 고정-고정, 고정-회전 및 회전-회전 보-기둥의 고유진동수 및 좌굴하중을 산출하였다. 수치해석의 결과로 무차원 고유진동수와 무차원 변수들 사이의 관계 및 무차원 좌굴하중과 단면비 사이의 관계를 그림에 나타내었고, 최강기둥의 단면비와 좌굴하중을 구하였다.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2002년도 추계학술대회논문집
• /
• pp.1054-1059
• /
• 2002

A linearly tapered beam immersed partially in other material is considered and is modelled as a linearly tapered Bernoulli-Euler beam fixed at the bottom with a concentrated mass at the top. Its governing equations is derived and its free vibration analysis is performed for various boundary conditions. And the rotatory inertia of the eccentric lumped tip mass is considered. The problem of determining the natural frequencies leads to an eighth order determinant. The solutions of the frequency equations are obtained numerically. The non-dimensional frequency parameters are given in tabular form and the influence of non-dimensional parameters on natural frequency is discussed for various conditions.

• Structural Engineering and Mechanics
• /
• 제48권2호
• /
• pp.195-205
• /
• 2013

The buckling problem of linearly tapered micro-columns is investigated on the basis of modified strain gradient elasticity theory. Bernoulli-Euler beam theory is used to model the non-uniform micro column. Rayleigh-Ritz solution method is utilized to obtain the critical buckling loads of the tapered cantilever micro-columns for different taper ratios. Some comparative results for the cases of rectangular and circular cross-sections are presented in graphical and tabular form to show the differences between the results obtained by modified strain gradient elasticity theory and those achieved by modified couple stress and classical theories. From the results, it is observed that the differences between critical buckling loads achieved by classical and those predicted by non-classical theories are considerable for smaller values of the ratio of the micro-column thickness (or diameter) at its bottom end to the additional material length scale parameters and the differences also increase due to increasing of the taper ratio.

• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 2006년도 정기 학술대회 논문집
• /
• pp.949-954
• /
• 2006

The purpose of this paper is to investigate the stability of tapered columns with clamped one end and carrying a tip mass of rotatory inertia with translational elastic support at the other end. The linearly tapered columns with the solid rectangular cross-section is adopted as the column taper. The differential equation governing free vibrations of such Beck columns is derived using the Bernoulli-Euler beam theory. Both the divergence and flutter critical loads are calculated from the load-frequency curves which are obtained by solving the differential equation. The critical loads are presented as functions of various non-dimensional system parameters: the taper type, the subtangential parameter, mass ratio and spring stiffness.

• Structural Engineering and Mechanics
• /
• 제10권5호
• /
• pp.479-489
• /
• 2000

Based on the stiffness equation of the tapered beam element involving the effects of axial force and shear deformation, numerical investigations are carried out on elastic instability for web-linearly tapered columns with I-section of steel portal frames. Effects of shear deformation on the effective length of the tapered columns with I-section are studied. An efficient approach for determining the effective length of the tapered portal frame columns considering effects of shear deformation is proposed.

• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 2007년도 정기 학술대회 논문집
• /
• pp.223-226
• /
• 2007

In current specification, modification factor(B) for web-tapered beam is used to account for the stress gradient and the restraining effect for adjacent spans. However, because these effects are considered together in modification factor, this paper revaluate the accuracy of the modification factor used in current specification. Also this paper investigate the flexural torsional buckling strength of laterally fixed thin-walled arch with doubly symmetric section using the analytical and numerical method. From this investigate the concept of effective length to consider the out-of-plane boundary condition for straight column or beam is not applicate for the flexural-torsional buckling of laterally fixed arches.