• Title/Summary/Keyword: end-member

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Evaluation of Structural Behavior of Tapered Member with Snug-tightened Flush End-plate Connection (밀착조임 볼트체결방법에 따른 엔드플레이트 접합부의 구조성능평가)

  • Chung, Kyung-Soo;Kim, Woo-Sik;Park, Man-Woo;Do, Byung-Ho
    • Journal of Korean Society of Steel Construction
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    • v.22 no.2
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    • pp.121-128
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    • 2010
  • The current trends in steel construction involve the use of tapered sections to minimize the use of excess materials to the extent possible, by choosing cross-sections that are as economical as possible abandoning the classical approach of using prismatic members. In addition, snug-tightened connections, especially the end-plate type, have the advantage of fetching less construction costs and shorter assembly times as opposed to fully tightened joints. Although they have many merits, however, snug-tightened bolted end plates are extremely complex in their structural behavior. In this study, an experimental investigation of the snug-tightened flush end-plate connections of tapered beams were conducted. The primary test parameters were the torque for the clamping bolt, the loading pattern, the bolt type and the connection failure type. Using initial stiffness and load-carrying capacity as proposed by Silva et al. and AISC (2003), the moment-rotation curve of a linearly tapered member with a snug-tightened flush end-plate connection was predicted. Moreover, numerical and experimental data for moment-rotation curves were compared.

Design Modification of the Stamping Die for the Improvement of Surface Quality of the Front End Module Carrier Upper Member (프런트 엔드 모듈 캐리어 어퍼 부재의 면품질 개선을 위한 금형설계 변경)

  • Kim S. H.
    • Transactions of Materials Processing
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    • v.14 no.2 s.74
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    • pp.153-159
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    • 2005
  • Design modification of the stamping die for the upper member of a front end module carrier is carried out in order to improve the surface quality of the final product. The small inferiority induced by wrinkling near the wall of the upper member has been inspected after the draw-forming process. The finite element analysis is pursued with the whole geometry in order to consider the complicated shape. The simulation shows that the excess metal is developed by the irregular contact of the blank the tool and it remains after the final stroke. This paper proposes two guidelines for the modification. One is to add the draw-bead near the critical region in order to increase the draw-in force. The other is to modify the tool shape such as the forming shape at the wall in order to absorb the excess metal before the final stroke. Simulation results show that the proposed guidelines both guarantee the improved surface quality.

Practical second-order analysis and design of single angle trusses by an equivalent imperfection approach

  • Cho, S.H.;Chan, S.L.
    • Steel and Composite Structures
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    • v.5 no.6
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    • pp.443-458
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    • 2005
  • Steel angles are widely used in roof trusses as web and chord members and in lattice towers. Very often angle members are connected eccentrically. As a result, not only an angle member is under an axial force, but it is also subject to a pair of end eccentric moments. Moreover, the connection at each end provides some fixity so neither pinned nor the fixed end represents the reality. Many national design codes allow for the effects due to eccentricities by modifying the slenderness ratio and reducing the compressive strength of the member. However, in practice, it is difficult to determine accurately the effective length. The concept behind this method is inconsistent with strength design of members of other cross-sectional types such as I or box sections of which the buckling strength is controlled by the Perry constant or the initial imperfection parameters. This paper proposes a method for design of angle frames and trusses by the second-order analysis. The equivalent initial imperfection-to-length ratios for equal and unequal angles to compensate the negligence of initial curvatures, load eccentricities and residual stresses are determined in this paper. From the obtained results, the values of imperfection-to-length ratios are suggested for design and analysis of angle steel trusses allowing for member buckling strength based on the Perry-Robertson formula.

Bumper Stay Design for Improving Frontal Crash Performance of Front Body (전방 차체의 정면 충돌성능 향상을 위한 범퍼 스테이 설계)

  • Kang, Sungjong
    • Journal of Auto-vehicle Safety Association
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    • v.6 no.2
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    • pp.5-11
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    • 2014
  • Front side member of the front impacted vehicle plays a key role in minimizing the impacting load transferred to the compartment. To perform that required function, axial collapse should be dominant during side member crashing and, prior to designing side member, it is crucial to minimize bending moment occurred at the front end. In this study, for FE model of a SUV front body, front impact analyses were carried to find out bumper stay design which effectively develope axial collapse in the side member. As a previous work, the thickness of side member reinforcement were changed. Next, the inner thickness of bumper stay was increased. Also, the bead shape and location were modified. Final front body model showed much more axial collapsed mode and enhanced crash performance. In addition, a stay of octagon section was adopted and that model exhibited distinctive increase in impact energy absorption.

Design of space truss structures

  • El-Sheikh, Ahmed
    • Structural Engineering and Mechanics
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    • v.6 no.2
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    • pp.185-200
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    • 1998
  • Space truss design usually involves two main assumptions: that truss members are pin-ended, and compression members possess brittle post-buckling characteristics. The validity of these assumptions in the design of a new group of space trusses with continuous chords and eccentric joints is questionable. With chord member continuity and the consequent improvement in compression member behaviour, current design practice might be too conservative. In this paper, it is shown that substantial improvements in overall truss strength have resulted when the true member end conditions are considered, thus indicating potential savings in truss weight with considerable magnitudes.

A Case Report of Pain Relief for Burn Patient through only Korean Medicine (한의 단독 치료를 통한 화상환자 통증 완화 치험 1례 증례 보고)

  • Kwon, Joong Chul;Na, Sam Sik;Chang, Sung Jin;Lee, Jae Heung
    • Journal of Korean Medical Ki-Gong Academy
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    • v.20 no.1
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    • pp.104-117
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    • 2020
  • Objective : The purpose of this study is to report that Korean Medicine treatment is effective in treating pain in burn patients. Results : We effectively reduced the pain that occurred after the end of the burn treatment through Korean Medicine such as multiple acupuncture, cupping, Sugi therapy, and external salve. VAS(Visual Analog Scale) values were reduced from 8 to 2 after about 23 days of treatment. Conclusions : This report shows that there was no special effect on dermatology treatment for pain that occurred after the end of treatment of burn patient, but it can also be excellent through Korean Medicine alone. It's only one case, so it cannot be determined that Korean Medicine for a burn is excellent. but if more excellent burn treatment of Korean Medicine is reported continuously, it will prove its validity. Therefore, it is hoped that more case reports and studies on burn treatments will be done in the future.

Energy Absorbing Characteristics of Thin-Walled Members for Vehicles Having Various Section Shapes (차체구조용 박육부재의 단면형상변화에 따른 에너지흡수 특성)

  • 차천석;정진오;이길성;백경윤;양인영
    • Journal of the Korean Society for Precision Engineering
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    • v.20 no.10
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    • pp.177-182
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    • 2003
  • The front-end side members of automobiles absorb most of the energy in a case of front-end collision. The front-end side members are required to have a high stiffness together with easiness to collapse sequentially to absorb more impact energy. The axial static collapse test (5mm/min) was conducted by using UTM for form different types of members which have different cross section shapes; single hat, single cap, double cap, and double hat. The single hat shaped section member has the typical standard section, which the double hat shape section has a symmetry in the center to have more stiffness. As a result of the test, the energy absorbing characteristic was analyzed for different section shapes. It turned out that the change of section shape influence the absorbing energy, the mean collapse load and the maximum collapse load, and the relation between the change of section shape and the collapse mode.

Energy Absorption Characteristics of Side Member for Light-weight Having Various Stacking Condition and Shape of Section (경량화용 사이드부재의 적층구성 및 단면형상 변화에 따른 에너지흡수 특성)

  • Lee, Kil-Sung;Seo, Hyeon-Kyeong;Yang, In-Young;Sim, Jae-Ki
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.31 no.6 s.261
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    • pp.671-678
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    • 2007
  • Front-side members of automobile, such as the hat shaped section members, are structures with the greatest energy absorbing capability in a front-end collision of vehicle. This paper was performed to analyze energy absorption characteristics of the hat shaped section members, which are basic shape of side member. The hat shaped section members consisted of the spot welded side member which was utilized to an actual vehicle and CFRP side member for lightweight of vehicle structural member. The members were tested under static axial loading by universal testing machine. Currently, stacking condition related to the collapse characteristics of composite materials is being considered as an issue fer the structural efficiency and safety of automobiles, aerospace vehicles, trains, ships even elevators during collision. So, energy absorption characteristics were analyzed according to stacking condition and shape of section and compared the results of spot welded side member with those of CFRP side member.

Crash Performance of Front Side Member Impacted with Angle (프론트 사이드 멤버의 경사 충돌 성능)

  • Kang, Sungjong
    • Transactions of the Korean Society of Automotive Engineers
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    • v.22 no.2
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    • pp.52-59
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    • 2014
  • Front impacted SUV vehicle shows that the front parts of side members are collapsed by the bending due to the transverse load exerted at the end of side members. Side member models were impacted with various angles in order to study the crash performance according to the impact angle. Even for the small impact angle of $10^{\circ}$, crash performance seriously deteriorated and the deformations for impact angle $15^{\circ}$ were similar to those from the front body impact analysis. In addition, the angled front impact analysis for the straight member with hat section was carried out and the effects of inner reinforcement shape on crash performance was investigated.

A Study on the Gurodae, archiectural member recorded on Yeonggeonuigwes and Sanleunguigwes (영건의궤 및 산릉의궤에 기록된 건축부재 구로대에 관한 연구)

  • Lee, Yeon-Ro
    • Journal of architectural history
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    • v.18 no.3
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    • pp.45-59
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    • 2009
  • This thesis mainly deals with what is th Gurodae, recorded of the YeonggeonUigwe and the SanleungUigwe. Gurodae makes diverse appearance In Uigwes.(久老代, 仇老代, 求路代, 仇老臺, 仇露臺, 求露臺, 仇累臺, 九累臺) It seems that Gurdae was an architectural member used on the roof. Especially that was a member of the eaves. Gurodae looks like a Pyeonggodae, located on the end of the rafters. But it differs in the shape compare to that of Pyeonggodae, Gurodae has the shape of combined members, Pyeonggoaed and Chakgo. Chakgo is a member covering the spae, between two Buyeons So Gurodae has the shape of prominence and depression. The result obtained by surveying the Uigwes is the Gurodae is the Gurodae used until 1789. After the publication of HyeonlyungwonUigwe in 1789, that member was no longer existed on the other Uigwes. In 1794, the making Hwaseong fortress, Gurodae divieed into two members, Chopyeonggodae and Chakgo. Since then Chopyeonggodae and Chakgo never combined again.

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