• Title/Summary/Keyword: Weight minimization

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A Study on the Weight Minimization of an Engine Block (엔진 블록의 중량 최소화에 관한 연구)

  • 오창근;박석주;박영범
    • Transactions of the Korean Society of Automotive Engineers
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    • v.5 no.3
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    • pp.182-190
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    • 1997
  • Recently to develope an automobile with better properties, much researches and investments are executed in many countries. In this paper, it is intended to minimize the weight of an engine block without changing the dynamic characteristics. The weight minimization is executed by the sensitivity of the natural frequency of the engine block. To decrease the engine weight, much less thickness than the original thickness of the engine is selected to initial value and the structure modification is performed to recover the dynamic characteristics of the engine. Here, the original thickness of the engine is 8mm and the initial thickness is selected to 5mm, 6mm and the number if the natural frequencies fitted are 2, 6, 7, respectively. As the results, it is found that; (1) the weight of each case could be reduced without changing the objective natural frequencies. Specially, in the case of fitting 2 natural frequencies with 5mm initial thickness the weight could be reduced to 4.21kg(23.3% for engine weight). (2) according to the driving frequency range of engine, the weight minimization could be performed choicely, (3) improving a vibration characteristics of a orignal structure, the weight minimization could be performed.

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A Circuit Design Using Weight Minimization Method (Weight 최소화법을 이용한 외로 설계)

  • 김희석;임제택
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.22 no.2
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    • pp.82-89
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    • 1985
  • A new non-inferior solution is obtained by investigating method of weight p- norm to explain the conception of MCO (multiple criterion optimization) problem. And then the optimum non-inferior solution is obtained by the weight minimization method applied to objective function of MOSFET NAND rATEAlso this weight minimization method using weight P- norm methods can be applied to non-convex objective function. The result of this minimization method shows the efficiency in comparison with that of Lightner.

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A study on the weight minimization of an engine block (엔진 블록의 중량 최소화에 관한 연구)

  • 오창근;박석주;박영범
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 1996.10a
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    • pp.231-236
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    • 1996
  • Recently to develope an automobile with better properties, much researches and investments are executed in many countries. In this paper, the weight of an engine block intend to minimize without changing the natural frequency. The weight minimization of an engine block is started from much less initial thickness than original thickness of the model and performed by using the sensitive analysis method and the optimum structural modification method. It can be considered that the weight minimization is completed through this process, because the optimum structural modification method includes the constraint of minimum changing quantity.

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Weight Minimization of a Beam Structure Using a Honeycomb Sandwich Panel (허니컴 샌드위치 패널을 이용한 보 구조물의 경량화에 관한 연구)

  • 성활경
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.06a
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    • pp.125-128
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    • 2003
  • In machine tool design, fast traversing cannot be achieved without reducing mass of the moving part. Honeycomb sandwich panel is extremely lightweight, and relatively rigid at the same time. We can reduce much weight when we selectively utilize honeycomb sandwich panels as stiffeners on machine tool structures. Feasibility of reducing weight is studied using a beam structure with both ends fixed.

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Optimal Location of Support Point for Weight Minimization in Radial Gate of Dam Structures (회전식 수문의 중량 최소화에 대한 지지점 위치의 최적설계)

  • Kwon, Young-Doo;Kwon, Soon-Bum;Goo, Nam-Seo;Jin, Seung-Bo
    • Proceedings of the KSME Conference
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    • 2000.11a
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    • pp.492-497
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    • 2000
  • This paper focuses on the weight minimization of radial gate, as an extention of the previous work. Radial gates are commonly used to regulate the flow-rate of general purpose dams, due to its simplicity in manufacture and control. The present study identifies the optimum position of support point for 2 and 3 arm type radial gate, which guarantees the minimum weight satisfying strength constraint condition. These optimum designs are then compared with previously constructed radial gates. The results indicate that the weights of the optimized radial gates reduce by about 20%, compared to those of the conventionally designed radial gates.

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Structural optimization with teaching-learning-based optimization algorithm

  • Dede, Tayfun;Ayvaz, Yusuf
    • Structural Engineering and Mechanics
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    • v.47 no.4
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    • pp.495-511
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    • 2013
  • In this paper, a new efficient optimization algorithm called Teaching-Learning-Based Optimization (TLBO) is used for the least weight design of trusses with continuous design variables. The TLBO algorithm is based on the effect of the influence of a teacher on the output of learners in a class. Several truss structures are analyzed to show the efficiency of the TLBO algorithm and the results are compared with those reported in the literature. It is concluded that the TLBO algorithm presented in this study can be effectively used in the weight minimization of truss structures.

Meta Model-Based Desgin Optimization of Double-Deck Train Carbody (2 층열차 차체의 meta model 기반 최적설계)

  • Hwang W.J.;Jung J.J.;Lee T.H.;Kim H.J.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.06a
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    • pp.387-392
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    • 2005
  • Double-deck train have studied in the next generation train in KRRI. Double-deck train have more seat capacities compared with single deck vehicles and is a efficient, reliable and comfortable alternative train. Because of heavy weight, weight minimization of double-deck train carbody is imperative to reduce cost and extend life-time of train. Weight minimization problem of the double-deck train car-body is required to decide 66 design variables of thicknesses for large aluminum extruded panel while satisfying stress constraints. Design variables are too many and one execution of structural analysis of double-deck train carbody is time-consuming. Therefore, we adopt approximation technique to save computational cost of optimization process. Metamodels such as response surface model (RSM) and kriging model are used to approximate model-based optimization is described. RSM is easy to obtain and expressed explicit function, but this is not suitable for highly nonlinear and large scaled problems. Kriging model employs an interpolation scheme and is developed in the fields of spatial statistics and geostatistics. Target of this design is to find optimum thickness of AEP to minimize weight of doulbe-deck train carbody. In this study, meta model techniques are introduced to carry out weight minimization of a double-deck train car-body.

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Weighted Mean Squared Error Minimization Approach to Dual Response Surface Optimization: A Process Capability Indices-Based Weighting Procedure (쌍대반응표면최적화를 위한 가중평균제곱오차 최소화법: 공정능력지수 기반의 가중치 결정)

  • Jeong, In-Jun
    • Journal of Korean Society for Quality Management
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    • v.42 no.4
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    • pp.685-700
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    • 2014
  • Purpose: The purpose of this paper is to develop a systematic weighting procedure based on process capability indices method applying weighted mean squared error minimization (WMSE) approach to dual response surface optimization. Methods: The proposed procedure consists of 5 steps. Step 1 is to prepare the alternative vectors. Step 2 is to rank the vectors based on process capability indices in a pairwise manner. Step 3 is to transform the pairwise rankings into the inequalities between the corresponding WMSE values. Step 4 is to obtain the weight value by calculating the inequalities. Or, step 5 is to obtain the weight value by minimizing the total violation amount, in case there is no weight value in step 4. Results: The typical 4 process capability indices, namely, $C_p$, $C_{pk}$, $C_{pm}$, $C_{pmk}$ are utilized for the proposed procedure. Conclusion: The proposed procedure can provide a weight value in WMSE based on the objective quality performance criteria, not on the decision maker's subjective judgments or experiences.

A Study on the Vibration Analysis of a Power Transmission by Substructure Synthesis Method (부분구조합성에 의한 동력전달기의 진동해석에 관한 연구)

  • 박석주;박성현;박영철
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2001.11a
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    • pp.161-166
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    • 2001
  • This study intends to reduce the weight of structure without changing the dynamic characteristics. At first, the Vibration analyses by the Substructure Synthesis Method and FEM using the ANSYS are performed for the engine speed converter to confirm the reliability of the analyzing tools. Weight minimization is performed by the Sensitivity Analysis and the Optimum Structural Modification. To decrease the converter weight ideally, the parts with low sensitivity are to be cut mainly, and the changing quantity of the natural frequency by the cut is to be recovered by the weight modification of the parts with high sensitivity. As the unique mathematical solution for the homogeneous problem( i.e. 0 object function problem) does not exist, the converter is redesigned with much thinner initial thickness. The goal of this study is to recover the dynamic characteristics of redesigned structure to those of the original one. To say in the other words, the modified structure has the same dynamic characteristics and the more lighter weight to compare with the original one. In this analysis, the modification was performed with the redesigned initial thickness of 60 mm and 70 mm. And the numbers of the interesting natural frequencies are 1, 2, 4 respectively. Consequently 27% of weight reduction effects were earned.

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A Study on the Weight Minimization of an Automobile Engine Block by Optimum Structural Modification (최적구조변경법에 의한 자동차 엔진 블록의 중량최소화에 관한 연구)

  • 길병래
    • Journal of Advanced Marine Engineering and Technology
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    • v.22 no.4
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    • pp.560-568
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    • 1998
  • Recently to develop an automobile with better properities many researches and investments have been executed. In this paper we intend to improve the automobile properties by reducing the weight of the engine without changing the dynamic characteristics. At first the vibration analysis by the Substructure Synthesis Mehtod and the exciting test of the engine model performed to confirm the reliability of the analyzing tools. And the weight minimiza-tion is performed by the Sensitivity Analysis and the Optimum Structural Modificationl. To decrease the engine weight ideally the weight of the parts with the low sensitivity is to cut mainly and the changing quantity of the natural frequency by the cut is to be recovered by the weight modification of the parts with the high sensitivity. As actually the mathematical unique solution for the homogeneous problem(i. e. 0 object func-tion problem)does not exist we redesign the engine block with much thinner initial thickness and recover the natural frequencies and natural modes of original structure by the sensitivity analy-sis and then observe the Frequency Response Function(FRF) for the interesting points. In this analysis the original thickness of the engine model is 8mm and the redesigned initial thicknesses are 5mm and 6mm, And the number of the interesting natural frequencies are 1, 2, 3, 4 and 5 respectively.

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