• Title, Summary, Keyword: Beam-Spring Model

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Spring Position and Stiffness Effect on the Dynamic Stability of Elastically Restrained Cantilevered Beams under a Follower Force (종동력을 받는 탄성지지된 외팔보의 동적 안정성에 미치는 스프링위치와 상수의 영향)

  • 류봉조;권경우;명태식
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.18 no.6
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    • pp.1496-1502
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    • 1994
  • The influences of spring position and spring stiffness on the critical force of a cantilevered beam subjected to a follower force are investigated. The spring attatched to the beam is assumed to be a translational one and can be located at arbitrary positions of the beam as it has not been assumed so far. The effects of transeverse shear deformation and rotary intertia of the beam are also included in this analysis. The charateristic equation for the system is derived and a finite element model of the beam using local coordinates is formulated through extended Hamilton's principle. It is found that when the spring is located at position less than that of 0.5L, the flutter type instability only exists. It is shown that the spring position approaches to the free end of the beam from its midpoint, instability type is changed from flutter to divergence through the jump phenomina according to the increase of spring stiffness.

Axial Stiffness Analysis of a Clutch Diaphragm Spring in Passenger Cars (승용차용 클러치 다이아프램 스프링의 축방향 강성해석)

  • Kim, J.Y.;Kim, J.G.;Yoon, H.J.
    • Journal of Power System Engineering
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    • v.14 no.6
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    • pp.35-40
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    • 2010
  • This article deals with the numerical analysis results of stiffness of diaphragm spring used in the clutch of a manual transmission. In order to investigate the relationship of the force and displacement in a diaphragm spring, we have established a numerical model of diaphragm spring using a well-known analytic model of Belleville spring and a cantilever beam model for the finger part of diaphragm spring. Using the stress and strain relations of Belleville spring and cantilever beam, we propose the analytic equation of motion of diaphragm spring for the use of a clutch automated actuator in an automated manual transmission. The proposed analytic model represents the typical dynamic characteristics of diaphragm spring along with the release bearing travel. And it is characterized in a closed-form equation, therefore it can be used for the further study of development of actuator and control law of clutch automating mechanism.

Error Analysis and Improvement of the Timoshenko Beam based Finite Element Model for Multi-Stepped Beam Structures (다단 보 구조에서의 티모센코 보 유한요소 모델링 오차분석 및 개선)

  • 홍성욱;이용덕;김만달
    • Journal of the Korean Society for Precision Engineering
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    • v.20 no.10
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    • pp.199-207
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    • 2003
  • The Timoshenko beam model has been known as the most accurate model for representing beam structures. However, the Timoshenko beam model may give rise to a significant error when it is applied to multi-stepped beam structures. This paper is intended to demonstrate the modeling error of Timoshenko beam based finite element model for multi-stepped beam structures and to suggest a new modeling method to improve the accuracy. A tentative bending spring is introduced into the stepped section to represent the softening effect due to the presence of step. This paper also proposes a finite element modeling method in the light with the tentative bending spring model for the step softening effect. The proposed method rigorously adapts computation results from a commercial finite element code. The validity of the proposed method is demonstrated through a series of simulation and experiment.

Improvement of the Timoshenko beam based finite element model for multi-stepped beam structures (다단 보 구조에서의 티모센코 보요소 모델링 오차 개선에 관한 연구)

  • 이용덕;홍성욱;이종원
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.788-791
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    • 2002
  • The Timoshenko beam model has been acknowledged as the most accurate model for representing beam structures. However, the Timoshenko beam model may give rise to significant error when it is applied to multi-stepped beam structures. This paper is intended to demonstrate and improve the modeling error of Timoshenko beam theory for multi-stepped team structures. A tentative bending spring is introduced to represent the stiffness change around a step in beams. This paper proposes a finite element modeling method in the light with the bending spring. The proposed method is rigorously compared with commercial finite element codes. The validity of the proposed method is also demonstrated through an experiment..

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Low-Frequency Vibration Analysis of a Center Pillar-to-Roof Rail Joint : Modelling Technique and Problems (센터 필라-루프 레일 조인트의 저진동 해석 : 모델링 기법과 문제점)

  • 김윤영;강정훈;송상헌
    • Transactions of the Korean Society of Automotive Engineers
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    • v.5 no.1
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    • pp.59-68
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    • 1997
  • The modelling techniques of a center pillar-to-roof rail joint for low frequency vibration analysis are examined and some fundamental problems are addressed. To develop a simplified beam-spring model of the joint, the present work is focused on 1) practical shell modelling techniques and 2) joint spring stiffness estimation methods a practical model-updating method to match the calculated natural frequencies to the experimentally determine ones is proposed, particularly focusing on spot welding modelling. In joint spring modelling, the results from the model with one joint spring are compared with those from the model with three coupled springs. Finally, some fundamental problems in beam-spring modelling are addressed.

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Failure mechanisms of a rigid-perfectly plastic cantilever with elastic deformation at its root subjected to tip pulse loading

  • Wang, B.
    • Structural Engineering and Mechanics
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    • v.2 no.2
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    • pp.141-156
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    • 1994
  • In this paper, the effect of material elasticity was evaluated through a simple model as proposed by Wang and Yu (1991), for yield mechanisms of a cantilever beam under tip pulse loading. The beam was assumed rigid-perfectly plastic but instead of the usual fully clamped constraints at its root, an elastic-perfectly plastic rotational spring was introduced there so the system had a certain capacity to absorb elastic energy. Compared with a rigid-perfectly plastic beam without a spring root, the present beam-spring model showed differences in the initial plastic hinge position and the minimum magnitude of the dynamic force needed to produce a plastic failure. It was also shown that various failure responses may happen while the hinge travels along the beam segment towards the root, rather than a unique response mode as in a rigid perfectly plastic analysis.

Static and Dynamic Analysis of Flexible Media Using Spring-Mass-Beam Model (스프링-매스-빔 모델을 이용한 유연매체의 정.동적 거동해석)

  • 지중근;정진우;홍성권;박노철;박영필
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.906-911
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    • 2004
  • In the development of sheet-handling machinery, it is important to be able to predict the italic and dynamic behavior of the sheets with a high degree of reliability because the sheets are fed and stacked at such a high speed. In this paper, a spring-mass-beam model is introduced. This model consists of rotational springs, shear springs and masses. The formulations for static and dynamic behavior of sheets are introduced. And some simulations are presented for static and dynamic cases.

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Modeling of progressive collapse of a multi-storey structure using a spring-mass-damper system

  • Yuan, Weifeng;Tan, Kang Hai
    • Structural Engineering and Mechanics
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    • v.37 no.1
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    • pp.79-93
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    • 2011
  • A simple mechanical model is proposed to demonstrate qualitatively the pancake progressive collapse of multi-storey structures. The impact between two collapsed storeys is simulated using a simple algorithm that builds on virtual mass-spring-damper system. To analyze various collapse modes, columns and beams are considered separately. Parametric studies show that the process of progressive collapse involves a large number of complex mechanisms. However, the proposed model provides a simple numerical tool to assess the overall behavior of collapse arising from a few initiating causes. Unique features, such as beam-to-beam connection failure criterion, and beam-to-column connection failure criterion are incorporated into the program. Besides, the criterion of local failure of structural members can also be easily incorporated into the proposed model.

The Relation of Bending Buckling Strength in Vehicle and Three Point Bending Maximum Strength of Door Impact Beam (도어 임팩트 빔의 3점 굽힘 최대강도와 차량 장착 시 굽힘 좌굴강도와의 관계)

  • Kang, Sungjong;Lee, Sangmin
    • Journal of Auto-vehicle Safety Association
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    • v.11 no.1
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    • pp.40-47
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    • 2019
  • First, three point bending analysis for the inclined press door impact beam was carried out to investigate inclination angle effect on the maximum strength with varying support distance. Next, for the system model with spring elements representing body stiffness at door mounting area, the bending structural behavior of impact beam mounted on vehicle was estimated. The mounting distance and inclination angle were changed and the beam bending buckling strength was presumed at the head displacement below which spring stiffness change has little effect on the load. Finally strength ratio to predict the bending buckling strength of impact beam mounted on vehicle from three point bending maximum strength of fixed support distance was suggested.

Frontal Crashworthiness Analysis of Vehicle Using simplified Structure Modelling (단순 차체 모델링을 이용한 차량 정면충돌해석)

  • 김홍수;강신유;이인혁;박신희;한동철
    • Transactions of the Korean Society of Automotive Engineers
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    • v.5 no.2
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    • pp.23-30
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    • 1997
  • Modelling and crashworthiness analysis of simplified vehicle structures with beam element and nonlinear spring element to which axial and bending collapse mecha- nisms are applied are carried out. And on the basis of these analyses, two types of full car modelling and crahworthiness analyses with nonlinear spring and beam element are accomplished. The one is the full car model of which 30% of the structures are modelled with nonlinear spring and beam element, and the other 75% of whole structures. And the results are compared with those of full car analysis with shell element.

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