• Title, Summary, Keyword: 설계 민감도해석

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Shape Design Sensitivity Analysis of Thermal Conduction Problems using Commercial Software ANSYS (상용 소프트웨어 ANSYS를 이용한 열전도문제의 형상설계 민감도 해석)

  • Choe, Ju-Ho
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.24 no.3
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    • pp.645-652
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    • 2000
  • A method for shape design sensitivity analysis is proposed utilizing commercial software ANSYS for thermal conduction problems. While the sensitivity formula is derived analytically by introduing adjoint variable concept, sensitivity calculation in practice as well as the primal and adjoint solution of thermal conduction is performed using the ANSYS very easily. Since the formula always takes boundary integral form, sensitivity evaluation in ANSYS requires a little more addition of post-processing routine which involves evaluation of boundary variable from the obtained solution. Though the BEM has been used as a better tool for this purpose, the present study shows it can also be calculated using any kind of analysis code such as ANSYS since the formula is based on analytic nature. Therefore the present study provides a new and efficient way of optimization which was not possible before using commercial software. The usefulness of the method is illustrated via a weight minimization problem of thermal diffuser.

Shape Design Sensitivity Analysis for Stability of Elastic Structures (탄성 구조물의 안정성을 고려한 형상설계민감도해석)

  • Choi, Joo-Ho
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.30 no.1
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    • pp.76-83
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    • 2006
  • This paper addresses the method for the shape design sensitivity analysis of the buckling load in the continuous elastic body. The sensitivity formula for critical load is analytically derived and expressed in terms of shape variation, based on the continuum formulation of the stability problem. Though the buckling problem is more efficiently solved by the structural elements such as beam and shell, the elastic solids are considered in this paper because the solid elements can be used in general for any kind of structures whether they are thick or thin. The initial stress and buckling analysis is carried out by the commercial analysis code ANSYS. The sensitivity is computed by using the mathematical package MATLAB using the results of ANSYS. Several problems including straight and curved beams under compressive load, ring under pressure load, thin-walled section and bottle shaped column are chosen to illustrate the efficiency of the presented method.

Analysis of Microwave Inverse Scattering Using the Broadband Electromagnetic waves (광대역 전자파를 이용한 역산란 해석 연구)

  • Lee, Jung-Hoon;Chung, Young-Seek
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
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    • pp.169-174
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    • 2005
  • In this paper, we proposed a new algorithm of the inverse scattering for the reconstruction of unknown dielectric scatterers using the finite-difference time-domain method and the design sensitivity analysis. We introduced the design sensitivity analysis based on the gradient for the fast convergence of the reconstruction. By introducing the adjoint variable method for the efficient calculation, we derived the adjoint variable equation. As an optimal algorithm we used the steepest descent method and reconstructed the dielectric targets using the iterative estimation. To verify our algorithm we will show the numerical examples for the two-dimensional $TM^2$ cases.

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Sensitivity of Hydraulic Structures Design Parameter by Climate Change (기후변화에 의한 수공구조물 설계인자 민감도 연구)

  • Kong, Jung-Sik;Kim, UlAnYi
    • Proceedings of the Korea Water Resources Association Conference
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    • pp.419-419
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    • 2011
  • 이상호우, 사막화, 빙하융해, 생태계 먹이사슬 변화, 이상기온 등 기후변화의 행태는 지구 곳곳에서 다양하게 발발되고 있으며 그로인해 발생되는 인적 물적 피해가 심각하다. 1996년 집중호우에 의한 연천댐체 파괴, 2002년 8월의 낙동강 유역 장기홍수, 2002년 태풍 루사 및 2003년 태풍 매미 등 국내에서는 기후변화 중에서도 주로 이상호우로 인해 발생하는 피해가 많았으며 이들은 주기성이나 특성을 갖지 않아 예측이 어려운 관계로 망양보뢰 식의 후처리에 급급한 실정이었다. 최근 기후변화에 따른 지역별 홍수량, 가뭄량 등에 관한 연구가 가속화되고 있으며, 이와 더불어 해당 기후모델 발현 시 기존 구조물에 미치는 영향에 대한 연구도 필수적이다. 나아가 기존 구조물 뿐 아니라 새로 시공되는 구조물의 설계에서 기후변화에 대한 안정성을 위해 추가적으로 포함해야 할 요소가 있는지에 대한 연구도 필요하다. 본 연구에서는 가상 기후모델에 대해 그 모델이 예측하는 홍수량이 실제 발현되었을 경우를 가정하여, 기존 수공구조물의 안정성에 미치는 영향을 살펴보고 영향인자의 민감도를 분석하고자 한다. 대상 수공구조물은 붕괴 시 영향력이 큰 정도를 기준으로 필댐, 콘크리트차수벽형석괴댐(CFRD), 콘크리트중력식댐, 제방으로 그 범주를 제한 하였으며 대상유역은 한강으로 가정하였다. 구조물의 안정성 검토방법은 각 구조물의 종류에 따라 상이하다. 흙이 주 재료인 제방과 필댐의 경우, 침투(Piping)와 비탈면(Sliding)에 대한 안정성 평가가 이루어지며 CFRD는 댐체와 벽체로 나누어 안정성평가를 하며 댐체 안정성 평가방법은 필댐과 유사하다. 본 연구에서는 하천설계기준(2009)과 댐설계기준(2005)에 따라 각 구조물의 기준안전율을 책정하였으며 점착력, 내부마찰각, 단위중량 등의 물성치는 해당 지역의 토질특성에 따라 여러 문헌을 참고하여 설정하였고 이를 SEEP/W, SLOPE/W 프로그램을 이용하여 구조해석을 실시하였다. 콘크리트중력식댐은 활동, 전도, 지지력에 대해 각각 안정성을 평가하며 MIDAS와 ABAQUS 프로그램을 병행하여 해석하였다. 민감도(Sensitivity)란 안정성에 영향을 미치는 설계인자들의 변화에 따라 안정성이 어떻게 변화하는 지를 말한다. 기후변화에 의한 수공구조물 설계인자 민감도 연구를 통해 기존 설계과정 또는 안정성 검토 시 해당인자의 기여도를 높이거나 새로운 설계인자를 추가하여 미래 상황에 대한 구조물의 위험 정도를 과거대비 상세히 예측할 수 있으며 나아가 적절한 대응 방안 제시에 기여하여 기후변화에 따른 피해를 감소할 수 있을 것이라고 생각된다.

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Reliability and Sensitivity Analysis for Laminated Composite Plate Using Response Surface Method (반응면 기법을 이용한 복합재 평판의 신뢰도 및 민감도해석)

  • Lee, Seokje;Jang, Moon-Ho;Kim, Jae-Ki;Moon, Jung-Won;Kim, In-Gul
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.37 no.4
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    • pp.461-466
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    • 2013
  • Advanced fiber-reinforced laminated composites are widely used in various fields of engineering to reduce weight. The material property of each ply is well known; specifically, it is known that ply is less reliable than metallic materials and very sensitive to the loading direction. Therefore, it is important to consider this uncertainty in the design of laminated composites. In this study, reliability analysis is conducted using COMSOL and MATLAB interactions for a laminated composite plate for the case in which the tip deflection is the design requirement and the material property is a random variable. Furthermore, the efficiency and accuracy of the approximation method is identified, and a probabilistic sensitivity analysis is conducted. As a result, we can prove the applicability of the advanced design method for the stabilizer of an underwater vehicle.

A Study on the Reduction of Over Head Crane′s Weight Considering Buckling, Vibration and Strength (좌굴, 진동, 강도를 고려한 천장크레인의 경량화에 관한 연구)

  • Hong, Do-Kwan;Ahn, Chan-Woo
    • Journal of Navigation and Port Research
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    • v.26 no.3
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    • pp.317-322
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    • 2002
  • In this study, structural optimum design was applied to the girder of magnet over head crane. The optimization was carried out using ANSYS Code for the deadweight of girder, especially focused on the thickness of its upper, lower, side and reinforced plates. The weight could be reduced up to around 15% with constraints of its deformation, stress, natural frequency and buckling strength. The structural safety was also verified by the buckling analysis of its panel structure. It might be thought to be very useful to design the conventional structures for the weight save through the structural optimization. Also this paper grasped the sensitivity influenced the design variables upon the objective function and the state variables.

Global Sensitivity Analysis of Joints for Plug-in Digital Framework (플러그인 디지털 프레임웍을 위한 연결부 전역민감도 해석)

  • Lee, Dooho;Won, Young-Woo;Kwon, Jong-Hyun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.40 no.5
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    • pp.483-488
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    • 2016
  • Plug-In Digital Framework is a system response analysis tool that is employed when system components are composed of black-box modules. Generally, the dynamic characteristics of joints between the system components significantly affect system responses, and they lead to displacement- and frequency-dependent stiffness and loss factor. Thus, the sensitivity of each joint parameters should be estimated from a global perspective. In this study, we introduce a global sensitivity analysis procedure under the Plug-In Digital Framework. To efficiently calculate the system responses, we introduce the frequency response function (FRF)-based substructuring method. Using the random balance designs (RBD), we generate the system responses and estimate the global first-order sensitivities for each joint stiffness. We apply the proposed global sensitivity analysis method to an interior noise problem of a passenger car, and we evaluate the efficiency of the global sensitivity analysis method.

Optimal Design of Vehicle Suspenion Systems Using Sensitivity Analysis (민감도 해석을 이용한 현가장치의 동역학적 최적설계)

  • 탁태오
    • Transactions of the Korean Society of Automotive Engineers
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    • v.2 no.3
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    • pp.50-61
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    • 1994
  • A method for performing dynamic design sensitivity analysis of vehicle suspension systems which have three dimensional closed-loop kinematic structure is presented. A recursive form of equations of motion for a MacPherson suspension system is derived as basis for sensitivity analysis. By directly differentiating the equations of motion with respect to design variables, sensitivity equations are obtained. The direct generalize for the application of multibody dynamic sensitivity analysis. Based on the proposed sensitivity analysis, optimal design of a MacPherson suspension system is carried out taking unsprung mass, spring and damping coefficients as design variables.

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Analysis on Vibration Characteristics of Bus Body Structure using Sensitivity Analysis of Component Structures (부분구조의 민감도해석을 이용한 버스차체의 진동특성 분석)

  • Kim, Jin-Hui;Lee, Sang-Beom;Yim, Hong-Jae
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.354-357
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    • 2004
  • In this paper, a sensitivity analysis technique is presented for performing effective structural optimization of bus system. Design sensitivities are analyzed on natural frequency of bus substructures using super-element. Vibration modes of substructure, which large affect on the global vibration mode of bus B.I.W., are found through the sensitivity analysis using the chain rule. And design variables, which are determined from the sensitivity analysis, are changed through optimum design.

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Evaluation Concept of Progressive Collapse Sensitivity of Steel Moment Frame using Energy-based Approximate Analysis (에너지 기반 근사해석을 이용한 철골모멘트골조의 연쇄붕괴 민감도 평가방법)

  • Noh, Sam-Young;Park, Ki-Hwan;Lee, Sang-Yun
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.21 no.5
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    • pp.108-116
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    • 2017
  • In this study, the prototype structure of seismically designed steel moment frame was analyzed statically and dynamically in order to demonstrate the applicability of energy-based approximate analysis with the dynamic effect of sudden column loss in the evaluation of the collapse resistance and a method for assessing the sensitivity to progressive collapse was proposed. For the purpose of comparing the structural behavior of buildings with different structural systems, the sensitivity of the structure to the sudden removal of vertical members can be used as a significant measure. The energy-based approximate analysis prediction for the prototype structure considered in the study showed good agreement with the dynamic analysis result. In the sensitivity evaluation, the structural robustness index that indicates the ability of a structure to resist collapse induced by abnormal loads was used. It was confirmed that the proposed methods can be used conveniently and rationally in progressive collapse analysis and design.