• Title/Summary/Keyword: Stacking Design

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The Fall Impact test for Extraction of Optimal Stacking Section of Composite Safety Barrier for Bridge (복합소재 교량용 방호울타리의 최적 적층 단면 도출을 위한 낙하 충돌시험)

  • Hong, Kab-Eui;Jeon, Shin-Youl;Kim, Kee-Seung;Kim, Seung-Eock
    • Journal of the Korean Society for Advanced Composite Structures
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    • v.2 no.1
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    • pp.1-7
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    • 2011
  • In this study the optimal stacking section was selected by pendulum impact test for six different stacking sections of the composite safety barrier. The beam cross-section shape was determined through the poll on six different beam cross-section shapes. The six kinds of stacking design for the determined beam cross-section were suggested. CSM, DB, DBT and Roving fibers were used for stacking design. Horizontal beam and 3:1 sloped beam were modeled by using LS-DYNA. The fall impact simulation was carried out by using rectangular pendulum and cylinder pendulum. Optimal stacking section was determined by comparing and analyzing the impact simulation results.

A Design Procedure for a Multi-Stage Axial Compressor Using the Stage-Stacking Method (단축적방법을 이용한 다단 축류압축기의 설계)

  • 강동진
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.18 no.6
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    • pp.1598-1603
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    • 1994
  • A preliminary design procedure for a multi-stage axial compressor is developed, which is based on the stage-stacking method. It determines the flow coefficient which gives rise to the design conditions required such as pressure ratio, mass flow rate and rotational speed for a given specific mass flow rate at inlet to a compressor. With this flow coefficient, blade radii, every stage and compressor performance characterics such as stage pressure ratio, adiabatic efficiency etc. are calculated by stacking each stage performance characteristics. It is shown that there is an optimum number of stage which results in the maximum of compressor overall efficiency for a given specific mass flow rate at inlet to a compressor. A test design was tried for three different geometric design constraints, and comparison with a previous study shows that present procedure could be used reliably in determining the number of compressor stage in preliminary design stage.

Stacking Sequence Optimization of Composite Laminates for Railways Using Expert System (철도분야 응용을 위한 전문가 시스템을 이용한 복합적층판의 적층순서 최적설계)

  • Kim Jung-Seok
    • Journal of the Korean Society for Railway
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    • v.8 no.5
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    • pp.411-418
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    • 2005
  • This paper expounds the development of a user-friendly expert system for the optimal stacking sequence design of composite laminates subjected to the various rules constraints. The expert system was realized in the graphic-based design environment. Therefore, users can access and use the system easily. The optimal stacking sequence is obtained by means of integration of a genetic algorithm, finite element analysis. These systems were integrated with the rules of design heuristics under an expert system shell. The optimal stacking sequence combination for the application of interest is drawn from the discrete ply angles and design rules stored in the knowledge base of the expert system. For the integration and management of softwares, a graphic-based design environment that provides multi-tasking and graphic user interface capability is built.

A study on application techniques in design phase of applying a crossing stacking method of modular housing (모듈러 저층집합주거의 교차적층방식 설계 적용기술 연구)

  • Jun, Young-Hun;Lee, Young;Kim, Kyoon-Tai
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2014.11a
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    • pp.81-82
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    • 2014
  • Modular housing has many advantages such as economy, flexibility and reusability. The domestic modular housing of a continuous stacking method has been built in military facilities, and dormitories. However, there is a limit to present diversity of low-rise multi-family housing. A cross stacking method is a way to pursue diversity of that but there is a difficulty to apply it owe to lack of cases and related technologies. Therefore, the purpose of this study is to suggest application techniques in design phase of applying the crossing stacking method in advance.

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Analysis of Structure Type of Stacking Chair

  • Shin, Young-Sik
    • Journal of the Korea Furniture Society
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    • v.18 no.4
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    • pp.296-306
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    • 2007
  • As life style changes, the demand for stacking chairs are increasing as the use of event halls or outside furniture where people gather in crowd is increasing. Early stacking chairs were mainly made to pile up a great amount and store, but in modern days it also has a decorative purpose. Besides, the development of various new materials and applied technology of furniture manufacture, the structure and design of stacking chair is becoming more interesting. Basically, according to the structure of the leg, the form and method of piling up is decided. The structure of the leg means the location of the leg connected to the seat, and according to the location, it can be piled up as upper, front, or rotational type. Such is the way how stacking chairs are classified according to the location of the leg, with its basis; the structure of stacking chair is reviewed. Now, chair for piling up is overcoming its simple function, which aesthetic beauty or arrangement of color after piling up is being considered. Also, according to storing, moving, and the place of use, various designs are demanded. As people's interest in stacking chair is increasing, various research regarding design should continue.

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Discrete Optimization for Vibration Design of Composite Plates by Using Lamination Parameters

  • Honda, Shinya;Narita, Yoshihiro;Sasaki, Katsuhiko
    • Advanced Composite Materials
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    • v.18 no.4
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    • pp.297-314
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    • 2009
  • A design method is proposed to optimize the stacking sequence of laminated composite plates for desired vibration characteristics. The objective functions are the natural frequencies of the laminated plates, and three types of optimization problems are studied where the fundamental frequency and the difference of two adjacent frequencies are maximized, and the difference between the target and actual frequencies is minimized. The design variables are a set of discrete values of fiber orientation angles with prescribed increment in the layers of the plates. The four lamination parameters are used to describe the bending property of a symmetrically laminated plate, and are optimized by a gradient method in the first stage. A new technique is introduced in the second stage to convert from the optimum four lamination parameters into the stacking sequence that is composed of the optimum fiber orientation angles of all the layers. Plates are divided into sub-domains composed of the small number of layers and designed sequentially from outer domains. For each domain, the optimum angles are determined by minimizing the errors between the optimum lamination parameters obtained in the first step and the parameters for all possible discrete stacking sequence designs. It is shown in numerical examples that this design method can provide with accurate optimum solutions for the stacking sequence of vibrating composite plates with various boundary conditions.

Influence of Stacking Condition on Collision Safety of CFRP Side Member (적층구성이 CFRP 사이드 부재의 충돌안전성에 미치는 영향)

  • Hwang, Woo Chae;Yang, In Young
    • Journal of the Korean Society of Safety
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    • v.29 no.3
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    • pp.14-19
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    • 2014
  • The global demand for reduction in the weight of automobiles has led many countries to focus on the development of hybrid, eco-friendly, and electric cars. Reduction in the weight of materials can both increase fuel efficiency and maximize automobile performance. Therefore, the design of automobile should be inclined towards the safety aspects. but at the same time, it also consider reducing the structural weight of an automobile. In this study, CFRP side members with circular and double hat shaped section was manufactured. The impact collapse tests performed with change of the stacking condition, such as variation of interface number and outerlayer angle. The impact collapse load and absorbed energy were quantitatively analyzed according to the changes in section shapes and stacking condition. This analysis was performed to obtain design data that can be applied in the development of optimum lightweight members for automobiles.

Advanced Genetic Algrorithm Strategies in Optimal Design of Stiffened Composite Panels (보강된 복합재 패널의 최적설계를 위한 유전알고리듬의 연구)

  • Lee, Jong-Su
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.24 no.5 s.176
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    • pp.1193-1202
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    • 2000
  • The paper describes the use of genetic algorithms (GA's) to the minimum weight design of stiffened composite panels for buckling constraints. The proposed design problem is characterized by mixture of continuous and discrete design variables corresponding to panel elements and stacking sequence of laminates, respectively. Design space is multimodal and non-convex, thereby introducing the need for global search strategies. Advanced strategies in GA's such as directed crossover, multistage search and separated crossover are adopted to improve search ability and to save computational resource requirements. The paper explores the effectiveness of genetic algorithms and their advanced strategies in designing stiffened composite panels under various uniaxial compressive load conditions and the linrlit on stacking sequence of laminates.