• 한국해양공학회지
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• 제22권2호
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• pp.91-98
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• 2008

In order to establish a design guide for the bottom plate structure of a 4.3 ton aluminum planning boat, the feasibilities of bottom plate scantling of the ship are investigated based on the results of structural strength analysis and a simple equation and evaluation system are developed for initial structural design purposes. This study consists of 5 steps: First, the background, necessity, and purpose of this study are explained briefly, Second, the principal dimensions of this ship, the position of the considered bottom plate members and material characteristics are introduced. Third, the equivalent design pressure concept is introduced and evaluated based on experience and experimental data. Fourth, the strength of bottom plate members are examined using elasto-plastic nonlinear structural analysis, and response levels and several boundary conditions are reviewed based on the analysis results. Finally, in order to suggest design guides in respect to the ship's structural design, a simple design equation and evaluation system for bottom plate members are suggested for boats in the 4.3 ton aluminumboat range through the introduction of safety factorsbased on the ultimate design pressure concept.

• 한국농공학회논문집
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• 제46권4호
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• pp.25-36
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• 2004

This study was conducted to derive the design rainfall by the consecutive duration using the at-site frequency analysis. Using the errors, K-S tests and LH-moment ratios, Log Pearson type 3 (LP3) and Generalized Extreme Value (GEV) distributions of Gamma and Non-Gamma Family, respectively were identified as the optimal probability distributions among applied distributions. Parameters of GEV and LP3 distributions were estimated by the method of L and LH-moments and the Indirect method of moments respectively. Design rainfalls following the consecutive duration were derived by at-site frequency analysis using the observed and simulated data resulted from Monte Carlo techniques. Relative root-mean-square error (RRMSE) and relative efficiency (RE) in RRMSE for the design rainfall derived by at-site analysis in the observed and simulated data were computed and compared. It has shown that at-site frequency analysis by GEV distribution using L-moments is confirmed as more reliable than that of GEV and LP3 distributions using LH-moments and Indirect method of moments in view of relative efficiency.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1993년도 가을 학술발표회논문집
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• pp.120-127
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• 1993

This paper is concerned with the integrated computer program system aiming at efficiently performing the structural analysis and design. The developed computer program system is introduced and applied to a simple two-dimensional structure to show the general concept of the integrated system. Some design modifications and re-analyses are illustrated including local mesh refinement, These show the efficiency in doing design modification and analysis.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 A
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• pp.181-183
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• 1997

In this paper the analysis and optimum design of ceramic insulator is studied. The finite element method (FEM) is used for the electromagnetic solution and the design sensitivity analysis is used for the optimization. The parameterization of design variables and movable points is introduced and the linear function is used as a interpolation function.

• 전산구조공학
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• 제25권4호
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• pp.63-70
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• 2012

This article introduces ADAPT Corporation's latest software product for the integrated multistory analysis and design of concrete buildings, ADAPT Edge. Edge uniquely packages user-friendly modeling of multistory buildings, accurate gravity and lateral analysis, post-tensioning, and detailed slab and beam design, all in one software package. The benefits of Edge over traditional concrete design software are explained.

• Steel and Composite Structures
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• 제2권2호
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• pp.113-128
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• 2002

The performance of steel MRF with rigid connections, proportioned by adopting different capacity design criteria, is evaluated in order to highlight the effectiveness of static non-linear procedure in predicting the structural seismic behavior. In the framework of the performance-based design, some considerations are made on the basis of the results obtained by both dynamic time histories and push-over analyses, particularly with reference to the damage level and the structure ability to withstand a strong earthquake.

• 한국융합학회논문지
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• 제8권4호
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• pp.189-197
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• 2017

자동차 구조 요소 설계에서 설계 엔지니어에게 주어진 가장 중요한 과업중 하나는 요소의 수명을 결정하고 그 요소가 좌굴하지 않도록 개선하는 것이다. 이렇게 하려면, 설계 엔지니어는 개념 설계 단계에서부터 부분 형상을 만들어 가기 위해 간단한 부분 해석을 먼저 시행해야 한다. 그리고 응력 레벨을 위한 보다 진보된 해석을 사용해야 한다. 이 단계에서 해석은 하중 경로와 총 응력 레벨의 총체적 거동을 이해하는데 집중되어야 한다. 구조의 강성 해석을 위한 최적의 모델은 설계 과정에서 응력 정보의 적절한 레벨을 제공한다. 보다 자세한 응력 해석을 하기 위해서 구조 모델은 응력 집중 또는 힘(또는 변위)분포 같은 자세한 국소 영역들을 가져야 한다. 본 연구는 자동차 차체 구조의 응력해석을 위한 설계 시 고려해야 할 사항들을 제시한 논문이다.

• KIEAE Journal
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• 제16권2호
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• pp.17-22
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• 2016

Purpose: Sensitivity analysis offers a good guideline for designing energy conscious buildings, which is fitted to a specific building configuration. Sensitivity analysis is, however, still too expensive to be a part of regular design process. The One-at-a-time (OAT) is the most common and simplest sensitivity analysis method. This study aims to propose a reasonable ground that the OAT can be an alternative method for the variance-based method in some early design scenarios, while the variance-based method is known adequate for dealing with nonlinear response and the effect of interactions between input variables, which are most cases in building energy simulations. Method: A test model representing the early design phase is built in the DOE2 energy simulations. Then sensitivity ranks between the OAT and the Variance-based methods are compared at three U.S. sites. Result: Parameters in the upper rank by the OAT do not much differ from those by the Main effect index. Considering design practices that designers would chose the most energy saving design option first, this rank similarity between two methods seems to be acceptable in the early design phase.

• 대한기계학회논문집A
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• 제29권11호
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• pp.1527-1533
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• 2005

Three methods for design sensitivity analysis such as finite difference method(FDM), direct differentiation method(DDM) and adjoint variable method(AVM) are well known. FDM and DDM for design sensitivity analysis cost too much when the number of design variables is too large. An AVM is required to compute adjoint variables from the simultaneous linear system equation, the so-called adjoint equation. Because the adjoint equation is independent of the number of design variables, an AVM is efficient for when number of design variables is too large. In this study, AVM has been extended to the eigenproblem of damped systems whose eigenvlaues and eigenvectors are complex numbers. Moreover, this method is implemented into a commercial finite element analysis program by means of the semi-analytical method to show applicability of the developed method into practical structural problems. The proposed_method is compared with FDM and verified its accuracy for analytical and practical cases.

• Tribology and Lubricants
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• 제28권5호
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• pp.197-202
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• 2012

In this study, with the purpose of fundamentally improving the unbalance response vibration of a large PRT motor-generator rotor by design, a performance improvement design analysis is carried-out by retrofitting tilting pad bearings, replacing the plain partial journal bearings that were originally applied for operation at a rated speed of 1,800 rpm. In this process, a goal of the design analysis is to obtain a design solution for maximizing the direct stiffness of the bearings while satisfying the key basic lubrication performance requirements such as the minimum lift-off speed and maximum oil-film temperature. The results show that with a careful design application of tilting pad journal bearings for operation at such a relatively low speed of 1,800 rpm, direct stiffness increment of the bearings by about two times can be effectively achieved. Prevention of pad unloading is also considered in the analysis. Moreover, the designs of elliptical and offset half journal bearings are also analyzed and reviewed.