• 제목/요약/키워드: Flexibility Structure

검색결과 795건 처리시간 0.029초

Dynamic Analysis and Optimal Design of Engine Mount Systems with Consideration of Foundation Flexibility

  • Lee, Sang-Beom;Yim, Hong-Jae;Lee, Jang-Moo
    • The Journal of the Acoustical Society of Korea
    • /
    • 제20권2E호
    • /
    • pp.51-58
    • /
    • 2001
  • Equations of motion of an engine mount system including foundation flexibility are derived. Forced vibration analysis is carried out for the given engine mount system excited with the unbalanced force and moment. A new optimal design method for the engine mount system is proposed, in which vibration characteristics of the chassis frame structure are considered as design parameters.

  • PDF

Generation of valley polarized current in graphene using quantum adiabatic pumping

  • Wang, Jing;Chan, K.S.
    • Advances in nano research
    • /
    • 제3권1호
    • /
    • pp.39-47
    • /
    • 2015
  • We study a device structure which can be used to generate pure valley current and valley polarized current using quantum adiabatic pumping. The design of the structure allows the flexibility of changing the structure from one for pure valley current generation to one for valley polarized current generation by changing the applied electric potentials through changing the symmetry of the structure. The device is useful for the development of valleytronic devices.

유연성과 강성을 고려한 최적구조설계

  • 민승재
    • 대한기계학회논문집A
    • /
    • 제21권9호
    • /
    • pp.1432-1440
    • /
    • 1997
  • The flexibility as well as the stiffness is required to perform mechanical function of a structure such as compliant mechanisms, which can be applied to MEMS(Micro-Electro-Mechanical Systems), flexible manufacturing devices, and design for no assembly. In this paper, the optimal design problem to achieve both structural flexibility and stiffness is formulated using multi-objective function, and the optimization problem is resolved by using Finite Element Method(FEM) and Sequential Linear Programming(SLP). Design examples of compliant mechanisms are presented to validate the design method.

Backbone NMR Assignments of WW2 domain from human AIP4

  • Seo, Min-Duk
    • 한국자기공명학회논문지
    • /
    • 제24권2호
    • /
    • pp.38-42
    • /
    • 2020
  • WW domains are small protein modules consisting of three-stranded antiparallel β-sheet, and involved in the protein-protein interaction for various biological systems. We overexpressed and purified WW2 domain from human AIP4/Itch (a member of Nedd4 family) using a pH/temperature dependent cleavage system. The backbone assignments of WW2 domain were completed, and secondary structure was predicted. Furthermore, backbone flexibility of WW2 domain was determined by 1H-15N heteronuclear NOE and amide hydrogen exchange experiments. The structural information would contribute to the structural determination of WW2 domain as well as the interaction study of WW2 domain with various binding partners.

유연한 베이스 플레이트로 지지되는 회전 유연 HDD 디스크-스핀들계의 유한 요소 진동 해석 (Finite Element Modal Analysis of a Spinning Flexible Disk-spindle System Supported by a Flexible Base Plate in a HDD)

  • 한재혁;장건희
    • 한국소음진동공학회:학술대회논문집
    • /
    • 한국소음진동공학회 2003년도 춘계학술대회논문집
    • /
    • pp.571-577
    • /
    • 2003
  • This research proposes a finite element method to determine the natural vibration characteristics of the spinning disk-spindle system in a HDD including the flexibility of supporting structure. Finite element equations of each substructure are derived with the introduction of consistent variables to satisfy the geometric compatibility at the internal boundaries. The natural frequencies and modes from the global asymmetric matrix equations of motion are determined by using the implicit restarted Arnoldi iteration method. The validity of the proposed method is verified by the experimental modal testing. It also shows that the flexibility of base plate plays an important role to determine the natural frequencies of the spinning disk-spindle system in a HDD.

  • PDF

Vibration analysis of steel frames with semi-rigid connections on an elastic foundation

  • Vu, Anh Q.;Leon, Roberto T.
    • Steel and Composite Structures
    • /
    • 제8권4호
    • /
    • pp.265-280
    • /
    • 2008
  • An investigation on the combined effect of foundation type, foundation flexibility, axial load and PR (semi-rigid) connections on the natural frequencies of steel frames is presented. These effects were investigated using a suitable modified FE program for cases where the foundation flexibility, foundation connectivity, and semi-rigid connections could be treated as equivalent linear springs. The effect of axial load on the natural frequency of a structure was found to be significant for slender structures subjected to high axial loads. In general, if columns of medium slenderness are designed without consideration of axial load effects, the frequency of the structure will be overestimated. Studies on the 3-story Los Angeles PR SAC frame indicate that the assumption of rigid connections at beam-column and column-base interfaces, as well as the assumption of a rigid foundation, can lead to significant errors if simplified design procedures are used. These errors in an equivalent static analysis are expected to lead to even more serious problems when considering the effect of higher modes under a non-linear dynamic analysis.

고인성 복합섬유 모르타르를 이용한 플랫 플레이트 구조 슬래브-기둥 접합부의 전단성능 개선 (Improvement of Shear Performance for High Ductile Fiber-Reinforced Mortar Slab-Column Connection in Flat Plate Structural System)

  • 하기주;김윤용;신종학;양승혁;홍건호;김정수
    • 한국콘크리트학회:학술대회논문집
    • /
    • 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
    • /
    • pp.145-148
    • /
    • 2005
  • Recently the construction of high-rise reinforced concrete building is progressively increased as the social demands. It is significantly important factors such as economy, the safety of structure, and the flexibility of internal space. Therefore new structural system is also required to be attained the reduction of story height, the flexibility and efficient use of space. The most suitable structural system is with the economy and flexibility, flat plate slab system in high-rise reinforced concrete building. In this research, it was focused in the improvement of shear performance in the flat plate system using high ductile fiber reinforced mortar. It was evaluated the shear performance in the critical region of slab-column connection. The flat plate system, designed by the high performance and safety, was developed as a new technique in the application of high-rise R/C building.

  • PDF

유연 구조물에서 반력 평가를 위해 요구되는 모드의 수 (On the Number of Modes Required to Observe Forces in Flexible Structures)

  • 김주형;김상섭
    • 대한기계학회:학술대회논문집
    • /
    • 대한기계학회 2001년도 추계학술대회논문집A
    • /
    • pp.562-567
    • /
    • 2001
  • The number of required modes to provide accurate force information in a truncated model of a flexible structure is investigated. In the case of modal truncation of a distributed parameter system, the difference in convergence rates between displacements and forces is discussed. The residual flexibility, a term from past literature, is used to recapture some of the lost force information in a truncated model. This paper presents numerical and experimental results of a study where the residual flexibility is used in conjunction with a Kalman filter so that accurate force information may be obtained from a small set of displacement measurements with a reduced-order model. The motivation for this paper is to be able to obtain accurate information about unmeasurable dynamic reaction forces in a rotating machine for diagnostic and control purposes.

  • PDF

유연 구조물에서 반력 평가를 위해 요구되는 모드의 수 (On the Number of Modes Required to Observe Forces in Flexible Structures)

  • 김주형;김상섭
    • 한국정밀공학회지
    • /
    • 제19권1호
    • /
    • pp.150-157
    • /
    • 2002
  • The number of required modes to provide accurate force information in a truncated model of a flexible structure is investigated. In the case of modal truncation of a distributed parameter system, the difference in convergence rates between displacements and forces is discussed. The residual flexibility. a term from past literature, is used to recapture some of the lost force information in a truncated model. This paper presents numerical and experimental results of a study where the residual flexibility is used in conjunction with a Kalman filter so that accurate force information may be obtained from a small set of displacement measurements wish a reduced-order model. The motivation for this paper is to be able to obtain accurate information about unmeasurable dynamic reaction forces in a rotating machine for diagnostic and control purposes.