• 제목/요약/키워드: hybrid strengthening

검색결과 62건 처리시간 0.024초

Interfacial stresses in RC beam bonded with a functionally graded material plate

  • Daouadji, Tahar Hassaine;Chedad, Abdebasset;Adim, Belkacem
    • Structural Engineering and Mechanics
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    • 제60권4호
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    • pp.693-705
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    • 2016
  • Functionally graded material (FGM) plates can be bonded to the soffit of a beam as a means of retrofitting the RC beam. In such plated beams, tensile forces develop in the bonded plate and these have to be transferred to the original beam via interfacial shear and normal stresses. In this paper, an interfacial stress analysis is presented for simply supported concrete beam bonded with a functionally graded material FGM plate. This new solution is intended for application to beams made of all kinds of materials bonded with a thin plate, while all existing solutions have been developed focusing on the strengthening of reinforced concrete beams, which allowed the omission of certain terms. It is shown that both the normal and shear stresses at the interface are influenced by the material and geometry parameters of the composite beam. This research is helpful for the understanding on mechanical behavior of the interface and design of the FGM-RC hybrid structures.

Renovation of steel beams using by imperfect functionally graded materials plate

  • Daouadji, Tahar Hassaine;Abderezak, Rabahi;Rabia, Benferhat;Tounsi, Abdelouahed
    • Steel and Composite Structures
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    • 제41권6호
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    • pp.851-860
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    • 2021
  • In this paper, a new approach of interface stress analysis in steel beam strengthened by porous FGM (Functionally Graded Materials) is presented to calculate the shear stress in the hybrid steel beam and loaded by a uniformly distributed load. The results show that there exists a high concentration of shear stress at the ends of the imperfect FGM, which might result in premature failure of the strengthening scheme at these locations. A parametric study has been conducted to investigate the sensitivity of interface behavior to parameters such as the rigidity of FGM plate (degree of homogeneity), the porosity index of FGM and the thickness of adhesive all were found to have a marked effect on the magnitude of maximum shear stress in the FGM member. we can conclude that the new approach is general in nature and may be applicable to all kinds of materials.

진공 플라즈마 스프레이 공정을 이용한 W계 복합 코팅층의 제조 및 특성 연구 (Manufacturing and Properties of Low Vacuum Plasma Sprayed W-Carbide Hybrid Coating Layer)

  • 조진현;진영민;안지훈;이기안
    • 한국분말재료학회지
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    • 제18권3호
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    • pp.226-237
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    • 2011
  • W-ZrC and W-HfC composite powders were fabricated by the Plasma Alloying & Spheroidization (PAS) method and the powders were sprayed into hybrid coating layers by using Low Vacuum Plasma Spray (LVPS) process, respectively. Microstructure, mechanical properties, and ablation characteristics of the fabricated coating layers were investigated. The LVPS process led to successful production of W-Carbide hybrid coatings, approximately 400 ${\mu}M$ or above in thickness. As the substrate preheating temperature increased from $870^{\circ}C$ to $917^{\circ}C$, the hardness of the W-ZrC coating layer increased due to decreased porosity. Vickers hardness showed higher value (about 108.4 HV) in W-ZrC hybrid coating material compared to that of W-HfC while adhesive strength was found to be similar in both coating layers. The plasma torch test revealed good ablation resistance of the W-Carbide hybrid coating layers. The relatively high performance W-ZrC coating layer at the elevated temperature is thought to be attributed to both the strengthening effect of ZrC particle remained in the layer and the formation of ZrO2 phase with high temperature stability.

하이브리드의 탈 장르화를 응용한 메이크업 디자인에 관한 연구(제 1보) (A Study on of Make-up Design with the Application of Genre Deconstruction in Hybrids (Ver. 1))

  • 방기정;김경희
    • 복식문화연구
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    • 제20권3호
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    • pp.347-362
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    • 2012
  • Formatively and artistically aspect, a hybrid can be said to be a phenomenon in which two mutually different genres are combined. Make-up is thought to be very important to arrange the foundation available for predicting and pursuing a flow and direction of future hybrid make-up based on this, by analyzing a flow centering on hybrid trend, which was shown previously. In terms of objectives of this study, the first, aim is to suggest a model for researching make-up by grasping the developmental process and the characteristics of hybrid art through considering an art theory of hybridity, shown in make-up. The second, aim is to design make-up by analyzing trends in make-up style after deconstructing the hybrid genre. The modern make-up design through genre-deconstruction characteristics beyond diverse plurality and genre could be known to be highlighted as aesthetic characteristic by a slight attempt as communication of open space, which connects culture and genre, which had failed to be recognized and was neglected. Empirical research has, produced a work by systematically arranging make-up design. This study, identifies two kind of barrier demolition, such as the class deconstruction and the temporal, spatial disorder centering on genre deconstruction of hybrid. There are infinite possibilities in developing make-up design in line with modern sensation through aesthetic element and symbolic significance through genre deconstruction. It was the expression mode in future make-up, to providing basic data, and to strengthening competitive edge of culture and art.

하이브리드의 탈 장르화를 응용한 메이크업 디자인에 관한 연구(제 2보) (A Study on Make-up Design with Application of Genre Deconstruction in Hybrid(Ver. 2))

  • 방기정;김경희
    • 패션비즈니스
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    • 제16권2호
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    • pp.88-107
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    • 2012
  • Hybrid implies that elements in more than two are combined, and is what is merged and used complexly the technologies and materials in several fields according to the development in scientific technology and the progress in technology. In the formative and artistic aspect, the hybrid can be said to be phenomenon that two of mutually different genres are combined. The function and form in each genre, which were combined at this time, are remained wholly or partially, thereby revealing as well without hiding a fact of having been combined. In the digital communication era, the same time level was integrated into one culture, with destroying the temporal·spatial boundary. As for the objectives of this study, first, the aim is to suggest a model for researching into make-up by grasping the developmental process and the characteristics of hybrid art through considering an art theory of hybrid, which was shown in make-up. Second, the aim is to design make-up by analyzing trend by make-up style after applying the genre deconstruction in hybrid. The modern make-up design through genre-deconstruction characteristics beyond diverse plurality and genre could be known to be highlighted as aesthetic characteristic by a slight attempt as communication of open space, which connects culture and genre, which had failed to be recognized and was neglected. Through the results of this study, it could be known that there is infinite possibility in developing make-up design in line with modern sensation through aesthetic element and symbolic significance through genre deconstruction. Based on these findings, its significance can be said to be in substantially contributing to offering new sight to the design & formative characteristic and the expression mode in future make-up, to providing basic data, and to strengthening competitive edge of culture and art.

Seismic retrofitting and fragility for damaged RC beam-column joints using UHP-HFRC

  • Trishna, Choudhury;Prem P., Bansal
    • Earthquakes and Structures
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    • 제23권5호
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    • pp.463-472
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    • 2022
  • Reinforced concrete (RC) beam column joints (BCJ) have mostly exhibited poor seismic performance during several past earthquakes, typically due to the poor-quality concrete or lack of reinforcement detailing typical of pre-code design practice. The present study is motivated towards numerical simulation and seismic fragility assessment of one such RC-BCJ. The BCJ is loaded to failure and strengthened using Ultra High Performance-Hybrid Fiber Reinforced Concrete (UHP-HFRC) jacketing. The strengthening is performed for four different BCJ specimens, each representing an intermediate damage state before collapse. viz., slight, moderate, severe, and collapse. From the numerical simulation of all the BCJ specimens, an attempt is made to correlate different modelling and design parameters of the BC joint with respect to the damage states. In addition, seismic fragility analysis of the original as well as the retrofitted damaged BCJ specimens show the relative enhancement achieved in each case.

Interfacial stresses in porous PFGM-RC hybrid beam

  • Benferhat Rabia;Hassaine Daouadji Tahar;Rabahi Abderezak
    • Advances in materials Research
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    • 제13권1호
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    • pp.37-53
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    • 2024
  • This paper presents a careful theoretical investigation into interfacial stresses in RC beams strengthened with externally bonded imperfect FGM plate. In this study, an original model is presented to predict and to determine the stresses concentration at the imperfect FGM end, with the new theory analysis approach. Stress distributions, depending on an inhomogeneity constant, were calculated and presented in forms. It is shown that both the shear and normal stresses at the interface are influenced by the material and geometry parameters of the composite beam, and it is shown that the inhomogeneities play an important role in the distribution of interfacial stresses. The theoretical predictions are compared with other existing solutions. The numerical resolution was finalized by taking into account the physical and geometric properties of materials that may play an important role in reducing the stress values. This research is helpful for the understanding on mechanical behaviour of the interface and design of the PFGM-RC hybrid structures.

Experimental and numerical investigations into the composite behaviour of steel frames and precast concrete infill panels with window openings

  • Teeuwen, P.A.;Kleinman, C.S.;Snijder, H.H.;Hofmeyer, H.
    • Steel and Composite Structures
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    • 제10권1호
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    • pp.1-21
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    • 2010
  • As an alternative for conventional structures for tall buildings, a hybrid lateral load resisting structure has been designed, enabling the assembly of tall buildings directly from a truck. It consists of steel frames with discretely connected precast concrete infill panels provided with window openings. Besides the stiffening and strengthening effect of the infill panels on the frame structure, economical benefits may be derived from saving costs on materials and labour, and from reducing construction time. In order to develop design rules for this type of structure, the hybrid infilled frame has recently been subjected to experimental and numerical analyses. Ten full-scale tests were performed on one-storey, one-bay, 3 by 3 m infilled frame structures, having different window opening geometries. Subsequently, the response of the full-scale experiments was simulated with the finite element program DIANA. The finite element simulations were performed taking into account non-linear material characteristics and geometrical non-linearity. The experiments show that discretely connected precast concrete panels provided with a window opening, can significantly improve the performance of steel frames. A comparison between the full-scale experiments and simulations shows that the finite element models enable simulating the elastic and plastic behaviour of the hybrid infilled frame.

9.77톤 전기복합 추진어선 저항 추진성능에 관한 연구 (A study on resistance & propulsion performance of a 9.77ton hybrid propulsion fishing boat)

  • 정영재;송연희;강혜영;이경완
    • 한국항해항만학회:학술대회논문집
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    • 한국항해항만학회 2023년도 추계학술대회
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    • pp.114-115
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    • 2023
  • 국제해사기구(IMO)의 해운분야 환경규제 강화에 의해 친환경선박에 대한 연구가 활발히 진행되고 있다. 그러나 대형 선박에 대한 연구가 대부분이며 소형선에 대한 연구는 미흡한 실정이다. 대부분의 어민들이 소형선을 운항하기 때문에 이에 대한 친환경 연료 선박 연구가 필요하다. 본 연구는 하이브리드 전기추진선 개발을 위해 저항성능 해석 및 모형시험, POW Test를 수행하였으며, CFD와 모형시험 결과 비교검증하였다.

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유사연성 하이브리드 FRP 시트를 이용한 RC 보의 휨 보강 (Pseudo-Ductile Hybrid FRP Sheet for Strengthening Reinforced Concrete Beams)

  • 하상수;최동욱;이진용;김길희
    • 콘크리트학회논문집
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    • 제20권2호
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    • pp.239-247
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    • 2008
  • 철근콘크리트 휨 부재 보강에 자주 사용하는 탄소섬유 대신 탄소섬유 및 유리섬유 두 가지를 동시에 사용, 보강된 콘크리트 휨 부재의 강도 및 연성을 증진시키는 방안을 연구하였다. 두 가지 섬유의 혼합비가 적절한 경우, 탄소섬유가 선파단하고 보다 큰 변형 및 응력에서 유리섬유가 순차적으로 파단하는 소위 유사연성거동을 보일 수 있다. 본 연구에 사용된 두 가지 섬유가 유사연성거동을 보일 수 있는 이론적인 혼합비는 4.62 : 1 (체적비)로 나타났다. 두 가지 섬유로 보강한 무근콘크리트보의 휨 실험에서 탄소섬유 :유리섬유 = 6.8 : 1 이상인 경우 유사연성거동이 나타남을 확인하였다. 체적비 8.8 : 1의 유리섬유-탄소섬유 하이브리드 시트를 제작하고, 철근콘크리트보를 보강한 후 휨 실험을 수행하였다. 하이브리드 시트 1겹 및 2겹으로 보강한 보에서 모두 무보강 보에 비하여 강도가 증진하는 반면에, 연성이 유지되는 결과를 확인하였다. 하이브리드 시트를 사용하면 탄소섬유를 사용한 보강에 비하여 보다 경제적이면서 탄소섬유와 동등 이상의 강도 및 보다 우수한 연성을 나타내었다. 하이브리드 시트를 사용한 휨 부재 보강에서 한 가지 섬유만을 사용하는 기존의 설계 방법을 적용하여도 보수적인 설계가 가능하였다.