• Title/Summary/Keyword: continuum

Search Result 1,368, Processing Time 0.021 seconds

Dynamic Equivalent Continuum Modeling of a Box-Beam Typed Wing (Box-Beam 형상 날개의 동적 등가연속체 모델링에 관한 연구)

  • 이우식;김영수
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.17 no.11
    • /
    • pp.2704-2710
    • /
    • 1993
  • A simple and straightforward method is introduced for developing continuum beam-rod model of a box-beam typed aircraft wing with composite layered skin based on "energy equivalence." The equivalent continuum structral properties are obtained from the direct comparison of the reduced stiffness and mass matrices for box-beam typed wing with those for continuum beam-rod model. The stiffness and mass matrices are all represented in terms of the continuum degrees-of freedom defined in this paper. The finite-element method. The advantage of the present continuum method is to give every continuum structural properties including all possible coupling terms which represent the couplings between different deformations. To evaluate the continuum method developed in this paper, free vibration analyses for both continuum beam-rod and box-beam are conducted. Numerical tests show that the present continuum method gives very reliable structural and dynamic properties compared to the results by the conventional finite-element analysis. analysis.

Continuum Modeling and dynamic Analysis of Platelike Truss Structures (평판형 트러스구조물의 연속체 모델링 및 동적해석)

  • 이우식;김종윤
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.16 no.6
    • /
    • pp.1021-1029
    • /
    • 1992
  • A rational and straightforward method is introduced for developing continuum models of large platelike periodic lattice structures based on energy equivalence. The procedure for developing continuum plate models involves the use of existing well-defined finite element matrices for the easy calculation of strain and kinetic energies of a repeating cell, from which the reduced stiffness and mass matrices are obtained in terms of continuum degrees- of-freedom defined in this paper. The equivalent continuum plate properties are obtained from the direct comparison of the reduced matrices for continuum plate with those for lattice plate. The advantages of the present continuum method are that it may be applied to arbitrary lattice configurations and may give most diverse equivalent continuum plate properties including all kinds of coupling, while other methods may give only limited structural properties. To evaluate the continuum method developed in this paper, free vibration analyses for both of continuum and lattice plates are conducted. Numerical results show that the present continuum method gives very reliable structural and dynamic properties compared to other well-recognized methods.

A Study on the Information Continuum Model: Preliminary Analysis to Establish the Relationship Between Records and Information (정보 컨티뉴엄 모델에 관한 연구: 기록과 정보 간의 관계 정립을 위한 예비적 분석)

  • Kim, Myoung-hun
    • Journal of Korean Society of Archives and Records Management
    • /
    • v.22 no.3
    • /
    • pp.21-36
    • /
    • 2022
  • This study intends to analyze the information continuum model as part of establishing the relationship between records and information. The information continuum is a theoretical system designed to establish a new information concept from the record-keeping point of view based on the record continuum. It provides a conceptual framework that can identify the elements for information management that exist in record-keeping. Accordingly, in Chapter 2, the background and process of the information continuum development, which followed after the record continuum development, were reviewed. Then, the concept of information established by borrowing information science theory was examined in relation to the record continuum. In Chapter 3, the conceptual structure of the information continuum and the purpose and method of information utilization were considered. Afterward, the four dimensions and attributes that structurally schematize the elements for information management in record-keeping were analyzed. Based on this analysis, Chapter 4 tried to present the meaning and limitations of the information continuum.

Aeroelastic Analyses of Aircraft Wing by Using Equivalent Continuum BeamalRod Model (등가연속체 Beam-Rod 모델을 이용한 항공기 날개의 공력탄성 해석)

  • Lee, U-Sik;Lee, Hang
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.19 no.3
    • /
    • pp.615-622
    • /
    • 1995
  • It may be inefficient to conduct the aeroelastic analysis by using full-scale conventional finite-element analyses or experiments, from the initial design phase, for an aircraft wing which can be considered as the discontinuum complex structure with composite laminated skins. In this paper, therefore more efficient aeroelastic analysis has been conducted for a box-beam typed aircraft wing by using the equivalent continuum beam-rod model which is derived from the concept of energy equivalence. Equivalent structural properties of the continuum beam-rod model are obtained from the direct comparison of the finite-element matrices of continuum beam-rod model with those of box-beam typed aircraft wing. Numerical results by the continuum beam-rod model approach are compared with those by the conventional finite-element analysis approach to show that the continuum beam-rod model proposed herein is quite satisfactory as a simplified model of aircraft wing structure for aeroelastic analyses.

Development of a 4-DOF Continuum Robot Using a Spring Backbone (스프링 구조를 이용한 4자유도 연속체 로봇의 개발)

  • Yoon, Hyun-Soo;Yi, Byung-Ju
    • The Journal of Korea Robotics Society
    • /
    • v.3 no.4
    • /
    • pp.323-330
    • /
    • 2008
  • This work deals with a 4-DOF flexible continuum robot that employs a spring as its backbone. The mechanism consists of two modules and each module has 2 DOF. The special features of the proposed mechanism are the flexibility and the backdrivability of the whole body by using a spring backbone. Thus, even in the case of collision with human body, this device can ensure safety. The design and the kinematics for this continuum mechanism are introduced. The performance of this continuum mechanism was shown through simulation and experiment.

  • PDF

CONTINUUM-WISE EXPANSIVENESS FOR C1 GENERIC VECTOR FIELDS

  • Manseob Lee
    • Journal of the Korean Mathematical Society
    • /
    • v.60 no.5
    • /
    • pp.987-998
    • /
    • 2023
  • It is shown that every continuum-wise expansive C1 generic vector field X on a compact connected smooth manifold M satisfies Axiom A and has no cycles, and every continuum-wise expansive homoclinic class of a C1 generic vector field X on a compact connected smooth manifold M is hyperbolic. Moreover, every continuum-wise expansive C1 generic divergence-free vector field X on a compact connected smooth manifold M is Anosov.

Characterization of Natvig Type Continuum Structure functions

  • Lee, Seung-Min
    • Proceedings of the Korean Reliability Society Conference
    • /
    • 2002.06a
    • /
    • pp.305-305
    • /
    • 2002
  • A continuum structure function is a non-decreasing mapping from the unit hypercube to the unit interval. Within the class of continuum structure functions, new axiomatic characterizations of the Natvig and the Barlow-Wu subclass are obtained.

  • PDF

Multiscale simulation based on kriging based finite element method

  • Sommanawat, Wichain;Kanok-Nukulchai, Worsak
    • Interaction and multiscale mechanics
    • /
    • v.2 no.4
    • /
    • pp.353-374
    • /
    • 2009
  • A new seamless multiscale simulation was developed for coupling the continuum model with its molecular dynamics. Kriging-based Finite Element Method (K-FEM) is employed to model the continuum base of the entire domain, while the molecular dynamics (MD) is confined in a localized domain of interest. In the coupling zone, where the MD domain overlaps the continuum model, the overall Hamiltonian is postulated by contributions from the continuum and the molecular overlays, based on a quartic spline scaling parameter. The displacement compatibility in this coupling zone is then enforced by the Lagrange multiplier technique. A multiple-time-step velocity Verlet algorithm is adopted for its time integration. The validation of the present method is reported through numerical tests of one dimensional atomic lattice. The results reveal that at the continuum/MD interface, the commonly reported spurious waves in the literature are effectively eliminated in this study. In addition, the smoothness of the transition from MD to the continuum can be significantly improved by either increasing the size of the coupling zone or expanding the nodal domain of influence associated with K-FEM.

A Study on the Manufacture of the Continuum Receiver System for Observing Cosmic Radio Waves (우주전파 관측용 연속파 수신시스템 제작에 관한 연구)

  • 서정빈;이창훈;임인성;한석태
    • Journal of the Korean Institute of Telematics and Electronics B
    • /
    • v.31B no.9
    • /
    • pp.67-75
    • /
    • 1994
  • In this paper, we manufactured the continuum receiver system for observing the continuum waves emitted from the continuum sources with using the 14m radio-telescope. The receiving system measures the total power of the continuum sources and consists of DC-amplifier, beam-chopper system. Phase-Locked Loop(PLL) circuit, blanking circuit and its period selection circuit, V/F converter, and counter part which are capable of interfacing with the computer which is used for a data acquisition and making the radio-telescope track the source. We compared the obsevation results which use the existing DVM method with the observation results which use the continuum receiver to measure the total power of the sources. Moreover, by method of beam switching observation which uses newly installed beam chopper system. We can significantly improve the observational efficiency more than the existing position switching observation method.

  • PDF

Reassessment on numerical results by the continuum model (연속체모델에 의한 수치해석결과에 대한 재평가)

  • Jeong, Jae-Dong;Yu, Ho-Seon;No, Seung-Tak;Lee, Jun-Sik
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.20 no.12
    • /
    • pp.3926-3937
    • /
    • 1996
  • In recent years there has been increased interest in the continuum model associated with the solidification of binary mixtures. A review of the literature, however, shows that the model verification was not sufficient or only qualitative. Present work is conducted for the reassessment of continuum model on the solidification problems of binary mixtures widely used for model validation. In spite of using the same continuum model, the results do not agree well with those of Incropera and co-workers which are benchmark problems typically used for validation of binary mixture solidification. Inferring from the agreement of present results with the analytic, experimental and other model's numerical results, this discrepancy seems to be caused by numerical errors in applying continuum model developed by Incropera and co-workers, not by the model itself. Careful examination should be preceded before selecting validation problems.