• Title/Summary/Keyword: impact design

검색결과 5,070건 처리시간 0.038초

방사성물질 수송용기 충격완충제 케이스의 좌굴변형에 의한 충격흡수효과 (Impact energy absorbing effect by the buckling of impact limiter's case of radioactive material transport cask)

  • 구정회;서기석;민덕기;김영진
    • 대한기계학회논문집A
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    • 제22권4호
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    • pp.826-833
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    • 1998
  • The energy-absorbing characteristic of impact limiters affects the cask design so significantly that it should be evaluated as accurate as possible. The objective of this study is to find the influence of the impact limiter's steel case and gusset plates which enclose the shock absorbing cellular material on the impact energy absorption. The influence of impact limiter's steel case and gusset plate stiffeners on the impact energy absorption behavior under horizontal drop impact was evaluated for a radioactive isotope transport cask. Though the impact limiters mitigate the impact damage of the cask, the impact limiter's steel case and gusset plate stiffeners increase the impact force so significantly that should be designed as soft as possible. The impact analysis without considering impact limiter's steel case and gusset plates stiffener gives non-conservative results, so the stiffness of the steel case and gusset plates should be considered in impact analysis.

A study on collision strength assessment of a jack-up rig with attendant vessel

  • Ma, Kuk Yeol;Kim, Jeong Hwan;Park, Joo Shin;Lee, Jae Myung;Seo, Jung Kwan
    • International Journal of Naval Architecture and Ocean Engineering
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    • 제12권1호
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    • pp.241-257
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    • 2020
  • The rapid proliferation of oil/gas drilling and wind turbine installations with jack-up rig-formed structures increases structural safety requirements, due to the greater risks of operational collisions during use of these structures. Therefore, current industrial practices and regulations have tended to increase the required accidental collision design loads (impact energies) for jack-up rigs. However, the existing simplified design approach tends to be limited to the design and prediction of local members due to the difficulty in applying the increased uniform impact energy to a brace member without regard for the member's position. It is therefore necessary to define accidental load estimation in terms of a reasonable collision scenario and its application to the structural response analysis. We found by a collision probabilistic approach that the kinetic energy ranged from a minimum of 9 MJ to a maximum 1049 MJ. Only 6% of these values are less than the 35 MJ recommendation of DNV-GL (2013). This study assumed and applied a representative design load of 196.2 MN for an impact load of 20,000 tons. Based on this design load, the detailed design of a leg structure was numerically verified via an FE analysis comprising three categories: linear analysis, buckling analysis and progressive collapse analysis. Based on the numerical results from this analysis, it was possible to predict the collapse mode and position of each member in relation to the collision load. This study provided a collision strength assessment between attendant vessels and a jack-up rig based on probabilistic collision scenarios and nonlinear structural analysis. The numerical results of this study also afforded reasonable evaluation criteria and specific evaluation procedures.

BIM 기반 터널 출구부 직광영향검토 Dynamo 알고리즘 개발 (Development of Dynamo Algorithm Based on BIM for Direct Sunlight Impact Analysis of Tunnel Outlet)

  • 권바름;염춘호
    • 한국BIM학회 논문집
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    • 제12권4호
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    • pp.41-51
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    • 2022
  • BIM was introduced under the leadership of public institutions, and projects such as road, railway, and site creation, including BIM tasks, are currently being ordered. In addition, as the Ministry of Land, Infrastructure and Transport(MOLIT) is pushing for the full design of BIM, public institutions under its jurisdiction are also pushing for the full design of BIM. Full design of BIM means that all designs are done with BIM. Public institutions' BIM guidelines only require BIM deliverables, and there is a limited direction for the BIM design process to respond to traditional design approaches. Therefore, it is necessary to develop a BIM-based design process corresponding to the full design of BIM.

CRITICAL SUCCESS FACTORS OF A BUILDING DESIGN TEAM

  • T.H. Nguyen;M. Diab
    • 국제학술발표논문집
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    • The 2th International Conference on Construction Engineering and Project Management
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    • pp.9-18
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    • 2007
  • The success of a building design team is achieved as a result of a combination of multiple events/factors and interactions, and has a great impact on the quality of the building construction process. While most of previous studies have focused on quality of the construction process, the success of a design team has not been completely investigated. This paper presents the critical factors that impact the success of a building design team and describes an assessment tool to measure the successful performance of the design team with respect to the critical factors. The development of the assessment tool employs the concept of quality function deployment (QFD), a technique to measure the service quality of an organization.

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플립칩의 설계변수 변화에 따른 보드레벨 플립칩에서의 낙하충격 수명예측 (Prediction of the Impact Lifetime for Board-Leveled Flip Chips by Changing the Design Parameters of the Solder Balls)

  • 이수진;김성걸
    • 한국생산제조학회지
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    • 제24권1호
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    • pp.117-123
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    • 2015
  • The need for drop simulations for board-leveled flip chips in micro-system packaging has been increasing. There have been many studies on flip chips with various solder ball compositions. However, studies on flip chips with Sn-1.0Ag-0.5Cu and Sn-3.0Ag-0.5Cu have rarely been attempted because of the unknown material properties. According to recent studies, drop simulations with these solder ball compositions have proven feasible. In this study, predictions of the impact lifetime by drop simulations are performed considering Cu and Cu/Ni UBMs using LS-DYNA to alter the design parameters of the flip chips, such as thickness of the flip chip and size of the solder ball. It was found that a smaller chip thickness, larger solder ball diameter, and using the Cu/Ni UBM can improve the drop lifetime of solder balls.

Comparative analyses of a shield building subjected to a large commercial aircraft impact between decoupling method and coupling method

  • Han, Pengfei;Liu, Jingbo;Fei, Bigang
    • Nuclear Engineering and Technology
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    • 제54권1호
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    • pp.326-342
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    • 2022
  • Comparative analyses of a shield building subjected to a large commercial aircraft impact between decoupling method and coupling method are performed in this paper. The decoupling method is applying impact force time-history curves on impact area of the shield building to study impact damage effects on structure. The coupling method is using a model including aircraft and shield building to perform simulation of the entire impact process. Impact force time-history curves of the fuselage, wing and engine and their total impact force time-history curve are obtained by the entire aircraft normally impacting the rigid wall. Taking aircraft structure and impact progress into account some loading areas are determined to perform some comparative analyses between decoupling method and coupling method, the calculation results including displacement, plastic strain of concrete and stress of steel plate in impact area are given. If the loading area is determined unreasonably, it will be difficult to assess impact damage of impact area even though the accurate impact force of each part of aircraft obtained already. The coupling method presented at last in this paper can more reasonably evaluate the dynamic response of the shield building than the decoupling methods used in the current nuclear engineering design.

Safety assessment of Generation III nuclear power plant buildings subjected to commercial aircraft crash Part I: FE model establishment and validations

  • Liu, X.;Wu, H.;Qu, Y.G.;Xu, Z.Y.;Sheng, J.H.;Fang, Q.
    • Nuclear Engineering and Technology
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    • 제52권2호
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    • pp.381-396
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    • 2020
  • Investigations of the commercial aircraft impact effect on nuclear island infrastructures have been drawing extensive attention, and this paper aims to perform the safety assessment of Generation III nuclear power plant (NPP) buildings subjected to typical commercial aircrafts crash. At present Part I, finite element (FE) models establishment and validations for both the aircrafts and NPP buildings are performed. (i) Airbus A320 and A380 aircrafts are selected as the representative medium and large commercial aircrafts, and the corresponding fine FE models including the skin, beam, fuel and etc. are established. By comparing the numerically derived impact force time-histories with the existing published literatures, the rationality of aircrafts models is verified. (ii) Fine FE model of the Chinese Zhejiang Sanao NPP buildings is established, including the detailed structures and reinforcing arrangement of both the containment and auxiliary buildings. (iii) By numerically reproducing the existing 1/7.5 scaled aircraft model impact tests on steel plate reinforced concrete (SC) panels and assessing the impact process and velocity time-history of aircraft model, as well as the damage and the maximum deflection of SC panels, the applicability of the existing three concrete constitutive models (i.e., K&C, Winfrith and CSC) are evaluated and the superiority of Winfrith model for SC panels under deformable missile impact is verified. The present work can provide beneficial reference for the integral aircraft crash analyses and structural damage assessment in the following two parts of this paper.

스프레더용 충격흡수기의 시스템 변화에 따른 최적설계 (The Optimum Design of Impact Absorbing System for Spreader in System Variations)

  • 홍도관;김동영;한동섭;안찬우;한근조
    • 한국항해항만학회지
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    • 제26권3호
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    • pp.311-316
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    • 2002
  • 본 연구에서는 항만하역장비인 스프레더용 충격흡수기의 개발을 위해 스프링과 오일댐퍼로 구성된 세 가지 형태의 모델에 대한 동적응답을 유한요소해석에 의해 수행하였다. 또한, 세 가지 모델의 충격흡수기에서 피스톤의 제한된 행정을 정적변수로 하고 목적함수인 충격에 대한 반력이 최소가 되도록 최적설계를 수행하였다. 본 연구의 결과로는 직렬식 2자유도계 모델의 반력이 가장 작게 나타났으며 그 다음으로는 1자유도계 모델, 병렬식 2자유도계 모델의 순으로 나타났다. 스프링상수와 감쇠계수의 변화가 반력에 미치는 영향을 확인하였으며, 최적설계 결과 각 모델에 대한 반력이 최소가 되는 스프링상수와 감쇠계수를 구하였다.

럭셔리 패션 브랜드의 디자인 특성에 따른 브랜드 태도와 구매의도에 관한 연구 (The Impact of Design Characteristics on Brand Attitude and Purchase Intention - Focus on Luxury Fashion Brands -)

  • 김지영;고은주
    • 한국의류학회지
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    • 제34권2호
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    • pp.252-265
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    • 2010
  • Most luxury fashion brands have a strong brand identity and the product design characteristics of a brand are critical factors that influence brand identity. The design of products influence brand identity and play an important role in the choice by consumers in which brand to purchase. This study investigates the impact design characteristics of luxury brands on brand attitudes as well as purchase intentions in the examination of the differences in the impact influence by product category and consumer characteristics. The product design of brands was evaluated and measured by innovative and traditional characteristics. The product categories were divided into apparel, bags, shoes, and accessories. The consumer characteristics used in this study are fashion involvement, age, income, and the amount of money used for purchasing fashion products. Sample brands, Louis Vuitton, Chanel, Hermes, Burberry, and Gucci, were extracted from the Intel-brand's Luxury Brand Ranking 2008 and pilot tested for appropriateness. The data collected from 120 luxury consumers and 92 samples were statistically analyzed with SPSS 15.0, reliability test, factor analysis, ANOVA, frequency test, regression, and t-test. The findings are as follow. First, luxury brands were divided into two groups by innovative design characteristics and traditional design characteristics; innovative design characteristics show a significant influence on brand attitude and purchase intention. Second, only fashion related behavior factors among consumer characteristics became moderators when design characteristics influenced brand attitude and purchase intention. Third, the differences in purchase intention affected by design characteristics were found in bags, shoes, and accessories category. It is necessary for luxury brands to focus on innovative design characteristics and to specify the different needs of consumers through fashion related behavioral factors. This research will be useful to luxury brands in designing products and planning marketing strategies by offering specific information for luxury brand consumers.