• Title/Summary/Keyword: Hybrid Structures

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A Study on the Modeling of the Response Analysis of Hybrid Structures (복합구조물의 응답해석을 위한 해석모델설정에 관한 연구)

  • 노희일;윤명호;권기혁;이춘호;서정원
    • Proceedings of the Korea Concrete Institute Conference
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    • 2000.10a
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    • pp.273-278
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    • 2000
  • These days, the number of residential-commercial buildings and apartments with pilotis is increasing. Generally, these buildings have a special structural called as Hybrid Structures consisting of upper-Walls and lower-Frames. However, this structures have some problems to be solved for the application of the regulation on the earthquake-resistant design and analysis techniques. Especially, in the case of irregular formal structures, engineers have to consider both the equivalent static analysis and the dynamic analysis. Thus, it is recommended to analyze those to inelastic region for economical reasons. In this paper, the method of modeling preceding the inelastic dynamic analysis using the DRAIN-2DX is presented to compare with those from MIDAS GENw program.

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Localized evaluation of actuator tracking for real-time hybrid simulation using frequency-domain indices

  • Xu, Weijie;Guo, Tong;Chen, Cheng
    • Structural Engineering and Mechanics
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    • v.62 no.5
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    • pp.631-642
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    • 2017
  • Accurate actuator tracking plays an important role in real-time hybrid simulation (RTHS) to ensure accurate and reliable experimental results. Frequency-domain evaluation index (FEI) interprets actuator tracking into amplitude and phase errors thus providing a promising tool for quantitative assessment of real-time hybrid simulation results. Previous applications of FEI successfully evaluated actuator tracking over the entire duration of the tests. In this study, FEI with moving window technique is explored to provide post-experiment localized actuator tracking assessment. Both moving window with and without overlap are investigated through computational simulations. The challenge is discussed for Fourier Transform to satisfy both time domain and frequency resolution for selected length of moving window. The required data window length for accuracy is shown to depend on the natural frequency and structural nonlinearity as well as the ground motion input for both moving windows with and without overlap. Moving window without overlap shows better computational efficiency and has potential for future online evaluation. Moving window with overlap however requires much more computational efforts and is more suitable for post-experiment evaluation. Existing RTHS data from Network Earthquake Engineering Simulation (NEES) is utilized to further demonstrate the effectiveness of the proposed approaches. It is demonstrated that with proper window size, FEI with moving window techniques enable accurate localized evaluation of actuator tracking for real-time hybrid simulation.

The Effects of Welding Wires on the Weldabilities of API X-100 with Laser-Arc Hybrid Welidng (API X-100의 레이저-아크 하이브리드 용접성에 미치는 용접와이어의 영향)

  • Kim, Sungwook;Lee, Mok-Young
    • Journal of Welding and Joining
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    • v.32 no.5
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    • pp.7-12
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    • 2014
  • In this study, API-X100 steel pipes were welded with various kinds of welding wires in the laser-arc hybrid welding process. 10kW fiber laser source was combined to MIG arc welding process. API X-100 steel of base metal was of 16.9mm thickness, and butt welding applied. After welding, full penetration weld was acquired by 1-pass welding. A root porosity and the lack of fusion was observed in some welding conditions. By the mixing the melted wire, acicular ferrite, polygonal ferrite, pro-eutectoid, aligned side plate, and bainite structures were observed at the weld metal. From the observation of hybrid weld, unmixed zone had more Ni and Cr. The unmixed zone was a 1/3 area of the weld metal. As the mechanical test of the hybrid welding, tensile test and impact test applied. From the tensile test, all of the welding except SM70S was fractured at the base metal. The result of the impact test at -30 degree C led 60J~320J of the absorbed energy. The result of the low-absorbed energy might be from the coarse equiaxed structures of the weld metal.

Improved prestressed concrete girder with hybrid segments system

  • Yim, Hong Jae;Yang, Jun Mo;Kim, Jin Kook
    • Structural Engineering and Mechanics
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    • v.65 no.2
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    • pp.183-190
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    • 2018
  • The prestressed concrete (PSC) technology that was first developed by Freyssinet has significantly improved over the past century in terms of materials and structural design in order to build longer, slender, and more economic structures. The application of prestressing method in structures, which is determined by the pre-tension or post-tension processes, is also affected by the surrounding conditions such as the construction site, workforce skills, and local transportation regulations. This study proposes a prestressed concrete girder design based on a hybrid segment concept. The adopted approach combines both pre-tension and post-tension methods along a simple span bridge girder. The girder was designed using newly developed 2400 MPa PS strands and 60 MPa high-strength concrete. The new concept and high strength materials allowed longer span, lower girder depth, less materials, and slender design without affecting the lateral stability of the girder. In order to validate the applicability of the proposed hybrid prestressed segments girder, a full-scale 35 m girder was fabricated, and experimental tests were performed under various fatigue and static loading conditions. The experimental results confirmed the feasibility of the proposed long-span girder as its performance meets the railway girder standards. In addition, the comparison between the measured load-displacement curve and the simulation results indicate that simulation analysis can predict the behavior of hybrid segments girders.

Hybrid displacement FE formulations including a hole

  • Leconte, Nicolas;Langrand, Bertrand;Markiewicz, Eric
    • Structural Engineering and Mechanics
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    • v.31 no.4
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    • pp.439-451
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    • 2009
  • The paper deals with the problem related to the modelling of riveted assemblies for crashworthiness analysis of full-scale complete aircraft structures. Comparisons between experiments and standard FE computations on high-energy accidental situations onto aluminium riveted panels show that macroscopic plastic strains are not sufficiently localised in the FE shells connected to rivet elements. The main reason is related to the structural embrittlement caused by holes, which are currently not modelled. Consequently, standard displacement FE models do not succeed in initialising and propagating the rupture in sheet metal plates and along rivet rows as observed in the experiments. However, the literature survey show that it is possible to formulate super-elements featuring defects that both give accurate singular strain fields and are compatible with standard displacement finite elements. These super-elements can be related to the displacement model of the hybrid-Trefftz principle of the finite element method, which is a kind of domain decomposition method. A feature of hybrid-Trefftz finite elements is that they are mainly used for elastic computations. It is thus proposed to investigate the possibility of formulating a hybrid displacement finite element, including the effects of a hole, dedicated to crashworthiness analysis of full-scale aeronautic structures.

Mechanical properties and production quality of hand-layup and vacuum infusion processed hybrid composite materials for GFRP marine structures

  • Kim, Sang-Young;Shim, Chun Sik;Sturtevant, Caleb;Kim, Dave Dae-Wook;Song, Ha Cheol
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.6 no.3
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    • pp.723-736
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    • 2014
  • Glass Fiber Reinforced Plastic (GFRP) structures are primarily manufactured using hand lay-up or vacuum infusion techniques, which are cost-effective for the construction of marine vessels. This paper aims to investigate the mechanical properties and failure mechanisms of the hybrid GFRP composites, formed by applying the hand lay-up processed exterior and the vacuum infusion processed interior layups, providing benefits for structural performance and ease of manufacturing. The hybrid GFRP composites contain one, two, and three vacuum infusion processed layer sets with consistent sets of hand lay-up processed layers. Mechanical properties assessed in this study include tensile, compressive and in-plane shear properties. Hybrid composites with three sets of vacuum infusion layers showed the highest tensile mechanical properties while those with two sets had the highest mechanical properties in compression. The batch homogeneity, for the GFRP fabrication processes, is evaluated using the experimentally obtained mechanical properties.

An inertia-type hybrid mount combining a rubber mount and a piezostack actuator for naval shipboard equipment

  • Moon, Seok-Jun;Choi, Sang-Min;Nguyen, Vien-Quoc;Oh, Jong-Seok;Choi, Seung-Bok;Chung, Jung-Hoon;Kwon, Jung-Il;Jung, Woo-Jin
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.5 no.1
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    • pp.62-80
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    • 2013
  • This paper has been focused on developing a new hybrid mount for shipboard equipment used in naval surface ships and submarines. While the hybrid mount studied in our previous research was 100 kg-class series-type mount, the new hybrid mount has been designed as an inertia-type mount capable of supporting a static of 500 kg. The proposed mount consists of a commercial rubber resilient mount, a piezostack actuator and an inertial mass. The piezostack actuator connected with the inertial mass generates actively the control force. The performances of the proposed mount with a newly designed specific controller have been evaluated in accordance with US military specifications and compared with the passive mount. An isolation system consisting of four proposed mounts and auxiliary devices has been also tested. Through a series of experimental tests, it has been confirmed that the proposed mount provides better performance than the US Navy's standard passive mounts.

Experimental Study on the Shear Capacity of the U-Flanged Truss Hybrid Beam With Reinforced End Zone (단부 보강에 따른 U-플랜지 트러스 복합보의 전단 내력에 관한 실험연구)

  • Kim, Young Ho;Park, Sung Jin;Oh, Myoung Ho
    • Journal of Korean Association for Spatial Structures
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    • v.21 no.1
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    • pp.71-78
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    • 2021
  • The U-flanged truss hybrid beam is a new composite beam made by pouring concrete into the U-flanged truss beam. In this study, an experimental study was performed to verify the shear capacity of U-flanged truss hybrid beams with the newly developed end reinforcement details. For all specimens, the maximum shear strength was determined by shear failure of concrete in the loading point The detail reinforced with stirrups at the end zone can exhibit the greatest shear strength, but the method of reinforcing the end zone using vertical steel plates, which is a relatively easy method to manufacture, is considered to be the most effective detail in terms of shear strength and ductility. Also, in the case of U-flanged truss hybrid beams reinforced with vertical steel plates at the end zone, the shear strength can be evaluated on the safety side by using the Korea Design Standard formula.

Experimental Structural Performance Evaluation of Hybrid Damper Combining with High Damping Rubber and Steel Slit (고감쇠고무와 강재슬릿이 결합된 하이브리드 댐퍼의 실험적 구조성능평가)

  • Lee, Joon-Ho;Park, Byung-Tae;Kim, Yu-Seong
    • Journal of Korean Association for Spatial Structures
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    • v.22 no.4
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    • pp.23-30
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    • 2022
  • It is effective to apply hybrid damping device that combine separate damping device to cope with various seismic load. In this study, HRS hybrid damper(hybrid rubber slit damper) in which high damping rubber and steel slit plate are combined in parallel was proposed and structural performance tests were performed to review the suitability for seismic performance. Cyclic Loading tests were performed in accordance with criteria presented in KDS 41 17 00 and MOE 2019. As a result of the test, the criteria of KDS 41 17 00 and MOE2019 was satisfied, and the amount of energy dissipation increased due to the shear deformation of the high-damping rubber at low displacement. Result of performing the RC frame test, the allowable story drift ratio was satisfied, and the amount of energy dissipation increased in the reinforced specimen compared to the non-reinforced specimen.

Hybrid Corrosion Inhibitor-Based Zwitterions and Phosphate in Reinforced Concrete: Determining Chloride Threshold and Service Life (철근 콘크리트의 Zwitterion 및 인산염 기반 하이브리드 부식 억제제: 염화물 임계값 및 사용 수명 결정)

  • Tran, Duc Thanh;Jeong, Min-Goo;Lee, Han-Seung;Yang, Hyun-Min;Singh, Jitendra Kumar
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2023.05a
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    • pp.33-34
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    • 2023
  • Corrosion of reinforcement steel is a major cause of deterioration in reinforced concrete (RC) structures. In order to protect these structures from corrosion, corrosion inhibitors are added to the concrete mix. In recent years, zwitterionic compounds have shown promising results as corrosion inhibitors in concrete due to their ability to form a protective layer on the surface of the reinforcement steel. The experimental study involves preparing concrete samples with different concentrations of adding the hybrid corrosion inhibitor at a high concentration of chloride ions. This study aims to determine the chloride threshold value and service life of hybrid corrosion inhibitors in reinforced concrete based on zwitterions. The samples are subjected to accelerated corrosion tests in a chloride environment to determine the threshold value and service life of the corrosion inhibitor. The effect of hybrid inhibitor on mechanical properties is guaranteed in allowable range. The chloride threshold concentration and service life of hybrid inhibitor containing samples perform greater than those of plain RC.

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