• Title/Summary/Keyword: Bending Performance Test

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Numerical Study on Performance Evaluation of Impact Beam for Automotive Side-Door using Fiber Metal Laminate (자동차 측면 도어의 섬유금속적층판을 적용한 임펙트 빔의 수치해석에 의한 성능 평가)

  • Park, Eu-Tteum;Kim, Jeong;Kang, Beom-Soo;Song, Woo-Jin
    • Composites Research
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    • v.30 no.2
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    • pp.158-164
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    • 2017
  • The fiber metal laminate is a type of hybrid materials laminated thin metallic sheets with fiber reinforced plastic sheets. The laminate has been researched or applied in automotive and aerospace industries due to their outstanding impact absorbing performance in view of light weight aspect. Specially, the replacement of side-impact beam as the fiber reinforced plastic has been researched actively. The objective of this paper is the primitive investigation in the development of side-door impact beam using the fiber metal laminate. First, the three-point bending simulations were conducted to decide the shape of impact beam using the numerical analysis. Next, two cases impact beam (pure DP 980 and fiber metal laminate) were installed in the side-door, and then the bending tests (according to FMVSS 214S) were simulated using the numerical analysis. It is noted that the side-door impact beam can be replaced with the fiber metal laminate sufficiently based on the numerical analysis results.

Effect of Bonding Process Conditions on the Interfacial Adhesion Energy of Al-Al Direct Bonds (접합 공정 조건이 Al-Al 접합의 계면접착에너지에 미치는 영향)

  • Kim, Jae-Won;Jeong, Myeong-Hyeok;Jang, Eun-Jung;Park, Sung-Cheol;Cakmak, Erkan;Kim, Bi-Oh;Matthias, Thorsten;Kim, Sung-Dong;Park, Young-Bae
    • Korean Journal of Materials Research
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    • v.20 no.6
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    • pp.319-325
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    • 2010
  • 3-D IC integration enables the smallest form factor and highest performance due to the shortest and most plentiful interconnects between chips. Direct metal bonding has several advantages over the solder-based bonding, including lower electrical resistivity, better electromigration resistance and more reduced interconnect RC delay, while high process temperature is one of the major bottlenecks of metal direct bonding because it can negatively influence device reliability and manufacturing yield. We performed quantitative analyses of the interfacial properties of Al-Al bonds with varying process parameters, bonding temperature, bonding time, and bonding environment. A 4-point bending method was used to measure the interfacial adhesion energy. The quantitative interfacial adhesion energy measured by a 4-point bending test shows 1.33, 2.25, and $6.44\;J/m^2$ for 400, 450, and $500^{\circ}C$, respectively, in a $N_2$ atmosphere. Increasing the bonding time from 1 to 4 hrs enhanced the interfacial fracture toughness while the effects of forming gas were negligible, which were correlated to the bonding interface analysis results. XPS depth analysis results on the delaminated interfaces showed that the relative area fraction of aluminum oxide to the pure aluminum phase near the bonding surfaces match well the variations of interfacial adhesion energies with bonding process conditions.

An Experimental Study on the Precast Segmented PSC Girder with I-Shape and Box-Shape Cross-Section (I형 단면과 BOX형 단면을 갖는 프리캐스트 분절 PSC 거더의 실험적 연구)

  • Kim, Sun-Hee;Lee, Seng-Hoo;Park, Joon-Seok;Cheon, Jinuk;Yoon, Soon-Jong
    • Journal of the Korean Society for Advanced Composite Structures
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    • v.6 no.2
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    • pp.8-16
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    • 2015
  • Prestressed concrete (PSC) is a method in which prestressed tendon is placed inside and/or outside the reinforced concrete member and the compressive force applied to the concrete in advance to enhance the engineering properties of concrete member which is weak under tension. In this paper we suggested the precast PSC girder assembled with segments of portable size and weight at the factory. The segments of precast PSC girder will be delivered and assembled as a unit of PSC girder at the site. Consequently, we suggested new-type of precast segmented PSC girder with different shapes of segment cross-section (i.e., I-shape, Box-shape). To mitigate the problems associated with the field splice between the segments of precast PSC girder anchor system is attached near the neutral axis of the girder and relatively uniform compression throughout the girder cross-section is applied. Prior to the experimental investigation, analytical investigation on the structural behavior of precast PSC girder was performed and the serviceability (deflection) and safety (strength) of the girder were confirmed. In addition, 4-point bending test on the girder was conducted to investigate the structural performance under bending. From the experimental investigation, it was found that the precast PSC girder spliced with 3 and 5 segments has sufficient in serviceability and safety conditions and it was also observed that the point where the segments spliced has no defects and the girder behaves as a unit.

Evaluation on the Impact Resistant Performance of Fiber Reinforced Concrete by High-Velocity Projectile and Contacted Explosion (고속비상체 충돌 및 접촉폭발에 의한 섬유보강 콘크리트의 내충격 성능 평가)

  • Nam, Jeong-Soo;Kim, Hong-Seop;Lee, In-Cheol;Miyauchi, Hiroyuki;Kim, Gyu-Yong
    • Journal of the Korea Concrete Institute
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    • v.25 no.1
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    • pp.107-114
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    • 2013
  • In this study we experimentally evaluated an impact resistant performance of fiber reinforced concrete in the moment of explosion by high-velocity projectile with emulsion explosive. To assess the impact resistance, we conducted the impact test of high-velocity projectile which reaches an impact speed of 350 m/s and the experiment of contact exploding emulsion explosive. As a result, bending and tensile performance depending on type of PVA, PE fiber (polyvinyl alcohol fiber, polyethylene fiber) and steel fiber affects destruction of rear side in the form of spalling. Destroying the backside of the concrete compressive strength compared to suppress the bending and tensile performance is affected. In addition, the experiment shows that the destruction patterns of concrete specimen producted by high velocity impact and contact explosion are significantly similar. Therefore, it is possible to predict the destruction patterns of specimens in the situation of contact explosion by high-velocity projectile.

Experimental and numerical analyses on axial cyclic behavior of H-section aluminium alloy members

  • Wu, Jinzhi;Zheng, Jianhua;Sun, Guojun;Chang, Xinquan
    • Structural Engineering and Mechanics
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    • v.81 no.1
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    • pp.11-28
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    • 2022
  • This paper considers the combination of cyclic and axial loads to investigate the hysteretic performance of H-section 6061-T6 aluminum alloy members. The hysteretic performance of aluminum alloy members is the basis for the seismic performance of aluminum alloy structures. Despite the prevalence of aluminum alloy reticulated shells structures worldwide, research into the seismic performance of aluminum alloy structures remains inadequate. To address this deficiency, we design and conduct cyclic axial load testing of three H-section members based on a reliable testing system. The influence of slenderness ratios and bending direction on the failure form, bearing capacity, and stiffness degradation of each member are analyzed. The experiment results show that overall buckling dominates the failure mechanism of all test members before local buckling occurs. As the load increases after overall buckling, the plasticity of the member develops, finally leading to local buckling and fracture failure. The results illustrate that the plasticity development of the local buckling position is the main reason for the stiffness degradation and failure of the member. Additionally, with the increase of the slenderness ratio, the energy-dissipation capacity and stiffness of the member decrease significantly. Simultaneously, a finite element model based on the Chaboche hybrid strengthening model is established according to the experiment, and the rationality of the constitutive model and validity of the finite element simulation method are verified. The parameter analysis of twenty-four members with different sections, slenderness ratios, bending directions, and boundary conditions are also carried out. Results show that the section size and boundary condition of the member have a significant influence on stiffness degradation and energy dissipation capacity. Based on the above, the appropriate material constitutive relationship and analysis method of H-section aluminum alloy members under cyclic loading are determined, providing a reference for the seismic design of aluminum alloy structures.

Seismic Performance Evaluation on Bending Deformation of 2-Ply and 3-Ply Bellows Expansion Pipe Joints (2겹 및 3겹 벨로우즈 신축배관이음의 휨 변형에 대한 내진성능평가 )

  • Sung-Wan Kim;Sung-Jin Chang;Dong-Uk Park;Bub-Gyu Jeon
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.27 no.2
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    • pp.33-41
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    • 2023
  • The application of seismic separation joints that can improve the deformation capacity of piping is an effective way to improve seismic performance. Seismic separation joints capable of axial expansion and bending deformation are installed where deformation is expected and used for the purpose of safely protecting the piping. Bellows are flexible and have low stiffness, so they can be used as seismic separation joints because they have excellent ability to respond to relatively large deformation. In this study, the seismic performance and limit state for bending deformation of 2-ply and 3-ply bellows specimens were evaluated. Seismic performance was evaluated by applying an increasing cyclic load to consider low-cycle fatigue due to seismic load. In order to confirm the margin for the limit state of the evaluated seismic performance, an experiment was conducted in which a cyclic loading of constant amplitude was applied. As a result of the experiment, it was confirmed that the bellows specimen was made of stainless steel and had a high elongation, so that the 2-ply bellows specimen had the limit performance of resisting within 3 cycles even at the maximum forced displacement of the 3-ply bellows specimen.

Design of Microstrip Antenna with Composite Laminates and its structural rigidity (복합재료 평면 안테나 구조의 제작 및 기계적 특성 평가)

  • 전지훈;유치상;김차겸;황운봉;박현철;박위상
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2002.05a
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    • pp.195-198
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    • 2002
  • Two types of conformal load-bearing antenna structure (CLAS) were designed with microwave composite laminates and Nomex honeycomb cores, to give both structural rigidity and good electrical performance. One is 4$\times$8 array for Synthetic Aperture Radar(SAR) system and the other is $5\times2$ array for wireless LAN system. Design was based on wide bandwidth, high polarization purity, low loss and good structural rigidity. We studied the design, fabrication and structural/electrical performances of the antenna structures. The flexural behavior was observed under a 3-point bending test, an impact test, and a buckling test. Electrical measurements were in good agreement with simulation results and these complex antenna structures have good flexural characteristics. The design of this antenna structure is extended to give a useful guide for sandwich panel manufacturers as well as antenna designers.

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A direct XFEM formulation for modeling of cohesive crack growth in concrete

  • Asferg, J.L.;Poulsen, P.N.;Nielsen, L.O.
    • Computers and Concrete
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    • v.4 no.2
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    • pp.83-100
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    • 2007
  • Applying a direct formulation for the enrichment of the displacement field an extended finite element (XFEM) scheme for modeling of cohesive crack growth is developed. Only elements cut by the crack is enriched and the scheme fits within the framework of standard FEM code. The scheme is implemented for the 3-node constant strain triangle (CST) and the 6-node linear strain triangle (LST). Modeling of standard concrete test cases such as fracture in the notched three point beam bending test (TPBT) and in the four point shear beam test (FPSB) illustrates the performance. The XFEM results show good agreement with results obtained by applying standard interface elements in FEM and with experimental results. In conjunction with criteria for crack growth local versus nonlocal computation of the crack growth direction is discussed.

Structural Performance of Reinforced Concrete Flat Plate Buildings Subjected to Fire

  • George, Sara J.;Tian, Ying
    • International Journal of Concrete Structures and Materials
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    • v.6 no.2
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    • pp.111-121
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    • 2012
  • The research presented in this paper analytically examines the fire performance of flat plate buildings. The modeling parameters for the mechanical and thermal properties of materials are calibrated from relevant test data to minimize the uncertainties involved in analysis. The calibrated models are then adopted to perform a nonlinear finite element simulation on a flat plate building subjected to fire. The analysis examines the characteristics of slab deflection, in-plane deformation, membrane force, bending moment redistribution, and slab rotational deformation near the supporting columns. The numerical simulation enables the understanding of structural performance of flat plate under elevated temperature and, more importantly, identifies the high risk of punching failure at slab-column connections that may trigger large-scale failure in flat plate structures.

Analysis of Buckling Characteristics for Hat Section Member Using Structural Foam and Plastic Reinforcement (구조용 폼과 플라스틱 보강재를 적용한 모자 단면 부재의 좌굴 특성 분석)

  • Lee, Tae-Hyun;Shin, Shoung-Gi
    • Transactions of the Korean Society of Automotive Engineers
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    • v.16 no.2
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    • pp.114-119
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    • 2008
  • The modern automotive industry develops innovative vehicle designs to meet increasing stability of car and performance demands of their customers. The improvement of frame rigidity by the structural foam is thought to be an effective means to improve the performance because of high applicability and minimum weight. The object of this paper is to examine the use of structural foam in a hat section as an optimum reinforcing means, to compare the reinforcing performance of structural foam versus a plastic reinforcement. The result of this paper indicated that reinforcing efficiencies are achieved by structural foam and plastic reinforcement shape.