• 제목/요약/키워드: Adherend

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단일겹치기이음시험을 이용한 합금화용융아연코팅강판의 코팅층 접합강도 평가 (Estimations of the Adhesion Strength of Galvannealed Coatings on Coated Sheet Using Single Lap-Shear Test)

  • 이정민;이찬주;고대철;이선봉;김병민
    • 대한기계학회논문집A
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    • 제33권6호
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    • pp.560-567
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    • 2009
  • This paper was designed to estimate the adhesion strength of galvannealed coatings on steel sheets. The adhesion strength were evaluated using single lap - shear tests where the lap joint was bonded by structural adhesive. Tests were performed for overlap length of 5mm, 10mm and 15 mm and three directions (0, 45, 90) of steel sheets used as the adherend of the overlap joint. After the tests, FE simulations of the single lap-shear test were also carried out to observe the stress distribution in the interface between the adhesive and the coated sheet. The results showed that the joint failure loads obtained from the tensile tests of bonded single lap-joints were the same, regardless of overlap lengths and directions of steel sheets. Also, the failure of galvannealed coatings greatly depended on shear stress distribution in the interface and the value was about 30MPa.

후판 단일 겹침 접착 조인트의 파손강도에 관한 연구 (A Study on Failure Strength of Single Lap Adhesive Joint with Thick Adherend)

  • 박재현;최진호;권진회
    • 한국항공우주학회지
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    • 제38권2호
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    • pp.111-118
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    • 2010
  • 복합재료 구조물에서 조인트 부위는 매우 취약한 부분이다. 본 논문에서는 후판 알루미늄-알루미늄 조인트 및 복합재-알루미늄 조인트를 접착제로 접합하여 제작한 다음, 인장실험을 수행하여 파손형태를 고찰하였다. 또한, 항복 변형률에 기초한 수정 파손영역 이론을 제안하였으며, 파괴모드별 파손하중과 상호 비교하였다. 후판 알루미늄-알루미늄 조인트와 복합재-알루미늄 조인트의 파손강도를 동일한 파손기준값을 적용하여 예측하였으며, 제작된 14종류의 시편에서는 최대 19.3% 오차범위 내에서 파손강도를 예측할 수 있었다.

The FEM Analysis of Recessing Location on the Stress Distribution in Aluminum Double Lap Joint

  • You, Min;Yan, Zhanmou;Zheng, Xiaoling;Yu, Haizhou
    • 접착 및 계면
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    • 제7권4호
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    • pp.13-17
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    • 2006
  • The elasto-plastic finite element method (FEM) was used to investigate the effect of off-center recessing location (8 mm length) on the stress distribution in the lap zone of adhesively bonded aluminium double lap joint. The results from simulation showed that the effect of off-cent recessing in bondline of double lap joint in the mid-bondline is not evidently to stress distribution in mid-bondline but the peak stresses both in mid-bondline and in the interface near the adherend side of the joint may increase markedly when an 8 mm length recessing was arranged symmetrical to the point of x =18 mm. When shifting an 8 mm length recess from near left end to the right end of the lap zone, all the highest peak stresses in the mid-bondline occurred under the condition of recess arranged symmetrical to the point of x = 6 mm.

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Analytical analysis of the interfacial shear stress in RC beams strengthened with prestressed exponentially-varying properties plate

  • Rabia, Benferhat;Abderezak, Rabahi;Daouadji, Tahar Hassaine;Abbes, Boussad;Belkacem, Adim;Abbes, Fazilay
    • Advances in materials Research
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    • 제7권1호
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    • pp.29-44
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    • 2018
  • In this paper, a closed-form rigorous solution for interfacial shear stress in simply supported beams strengthened with bonded prestressed E-FGM plates and subjected to an arbitrarily positioned single point load, or two symmetric point loads is developed using linear elastic theory. This improved 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. The theoretical predictions are compared with other existing solutions. Finally, numerical results from the present analysis are presented to study the effects of various parameters of the beams on the distributions of the interfacial shear stresses. The results of this study indicated that the E-FGM plate strengthening systems are effective in enhancing flexural behavior of the strengthened RC beams.

Effect of tapered-end shape of FRP sheets on stress concentration in strengthened beams

  • Belakhdar, Khalil;Tounsi, Abdelouahed;Adda Bedia, El Abbes;Redha, Yeghnem
    • Steel and Composite Structures
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    • 제11권6호
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    • pp.435-454
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    • 2011
  • Bonding composite materials to structural members for strengthening purpose has received a considerable attention in recent years. The major problem when using bonded FRP or steel plates to strengthen existing structures is the high interfacial stresses that may be built up near the plate ends which lead to premature failure of the structure. As a result, many researchers have developed several analytical methods to predict the interface performance of bonded repairs. In this paper, a numerical solution using finite - difference method is used to calculate the interfacial stress distribution in beams strengthened with FRP plate having a tapered ends with different thinning profiles. These latter, can significantly reduce the stress concentration. In the present theoretical analysis, the adherend shear deformations are taken into account by assuming a parabolic shear stress through the thickness of both beam and bonded plate. Numerical results from the present analysis are presented to demonstrate the advantages of use the tapers in design of strengthened beams.

Improved analytical solution for slip and interfacial stress in composite steel-concrete beam bonded with an adhesive

  • Tayeb, Bensatallah;Daouadji, Tahar Hassaine
    • Advances in materials Research
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    • 제9권2호
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    • pp.133-153
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    • 2020
  • In this paper, an improved theoretical interfacial stress and slip analysis is presented for simply supported composite steel-concrete beam bonded with an adhesive. The adherend shear deformations have been included in the present theoretical analyses by assuming a linear shear stress through the thickness of the adherends, while all existing solutions neglect this effect. Remarkable effect of shear deformations of elements has been noted in the results. It is observed that large shear is concentrated and slip at the edges of the composite steel-concrete. Comparing with some experimental results from references, analytical advantage of this improvement is possible to determine the normal and shear stress to estimate exact prediction of normal and shear stress interfacial along span between concrete and steel beam. The exact prediction of these stresses will be very important to make an accurate analysis of the mode of fracture. It is shown that both the normal and shear stresses at the interface are influenced by the material and geometry parameters of the composite steel-concrete beam. This research is helpful for the understanding on mechanical behavior of the connection and design of such structures.

유한요소법을 이용한 원통체의 점탄성 응력 해석 (Viscoelastic Stress Analysis of Adhesive-bonded Cylindrical by FEM)

  • 박승진
    • 한국재난정보학회 논문집
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    • 제15권2호
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    • pp.259-267
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    • 2019
  • 연구목적: 본 논문에서 접착제로 접착된 원통형 랩 접합부는 피착체가 탄성이고, 접착제가 선형 점탄성이라고 가정한다. 연구방법: 피착제의 응력 분포는 유한요소법을 사용하며, 4개의 아이소파라메터 점탄성 고체 접착제를 통해 피착제에 대한 해석결과를 검증한다. 연구결과: 접착층에서의 시간에 대한 응력분포와 피착제의 두께와 탄성율이 규격화에 미치는 응력의 영향을 검토한다. 결론: 본 연구는 접착제층의 점탄성을 고려한 랩접착된 원통체의 접착제층의 응력분포에 대해서 4요소 탄성체 모델을 사용하여 수치해석을 하였다.

Elastic analysis of interfacial stresses in prestressed PFGM-RC hybrid beams

  • Abderezak, Rabahi;Rabia, Benferhat;Daouadji, Tahar Hassaine;Abbes, Boussad;Belkacem, Adim;Abbes, Fazilay
    • Advances in materials Research
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    • 제7권2호
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    • pp.83-103
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    • 2018
  • In this paper, the problem of interfacial stresses in damaged reinforced concrete beams strengthened with bonded prestressed functionally graded material plate and subjected to a uniformly distributed load, arbitrarily positioned single point load, or two symmetric point loads is developed using linear elastic theory. The adopted model takes into account the adherend shear deformations by assuming a linear shear stress through the depth of the damaged RC beam. This solution is intended for application to beams made of all kinds of materials bonded with a thin FGM plate. The results show that there exists a high concentration of both shear and normal stress at the ends of the functionally graded material plate, which might result in premature failure of the strengthening scheme at these locations. Finally, numerical comparisons between the existing solutions and the present new solution enable a clear appreciation of the effects of various parameters of the beams on the distributions of the interfacial stresses.

Rehabilitation of RC structural elements: Application for continuous beams bonded by composite plate under a prestressing force

  • Abderezak, Rabahi;Rabia, Benferhat;Daouadji, Tahar Hassaine
    • Advances in materials Research
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    • 제11권2호
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    • pp.91-109
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    • 2022
  • This paper presents a closed-form higher-order analysis of interfacial shear stresses in RC continuous beams strengthened with bonded prestressed laminates. For retrofitting reinforced concrete continuous beams is to bond fiber reinforced prestressed composite plates to their tensile faces. An important failure mode of such plated beams is the debonding of the composite plates from the concrete due to high level of stress concentration in the adhesive at the ends of the composite plate. The model is based on equilibrium and deformations compatibility requirements in and all parts of the strengthened beam, where both the shear and normal stresses are assumed to be invariant across the adhesive layer thickness. In the present theoretical analysis, the adherend shear deformations are taken into account by assuming a parabolic shear stress through the thickness of both the RC continuous beams strengthened with bonded prestressed laminates. The theoretical predictions are compared with other existing solutions. A parametric study has been conducted to investigate the sensitivity of interface behavior to parameters such as laminate stiffness and the thickness of the laminate where all were found to have a marked effect on the magnitude of maximum shear and normal stress in the composite member.

Analysis and modeling of hyperstatic RC beam bonded by composite plate symmetrically loaded and supported

  • Abderezak, Rabahi;Daouadji, Tahar Hassaine;Rabia, Benferhat
    • Steel and Composite Structures
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    • 제45권4호
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    • pp.591-603
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    • 2022
  • The flexural strengthening of reinforced concrete beams by external bonding of composite materials has proved to be an efficient and practical technique. This paper presents a study on the flexural performance of reinforced concrete continuous beams with three spans (one span and two cantilevered) strengthened by bonding carbon fiber fabric (CFRP). The model is based on equilibrium and deformations compatibility requirements in and all parts of the strengthened continuous beam, i.e., the continuous concrete beam, the FRP plate and the adhesive layer. The adherend shear deformations have been included in the present theoretical analyses by assuming a linear shear stress through the thickness of the adherends. Remarkable effect of shear deformations of adherends has been noted in the results. The theoretical predictions are compared with other existing solutions that shows good agreement, and It shows the effectiveness of CFRP strips in enhancing shear capacity of continuous beam. 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.