• 제목/요약/키워드: Hybrid composite plate

검색결과 99건 처리시간 0.022초

Structural coupling mechanism of high strength steel and mild steel under multiaxial cyclic loading

  • Javidan, Fatemeh;Heidarpour, Amin;Zhao, Xiao-Ling;Al-Mahaidi, Riadh
    • Steel and Composite Structures
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    • 제27권2호
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    • pp.229-242
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    • 2018
  • High strength steel is widely used in industrial applications to improve the load-bearing capacity and reduce the overall weight and cost. To take advantage of the benefits of this type of steel in construction, an innovative hybrid fabricated member consisting of high strength steel tubes welded to mild steel plates has recently been developed. Component-scale uniaxial and multiaxial cyclic experiments have been conducted with simultaneous constant or varying axial compression loads using a multi-axial substructure testing facility. The structural interaction of high strength steel tubes with mild steel plates is investigated in terms of member capacity, strength and stiffness deterioration and the development of plastic hinges. The deterioration parameters of hybrid specimens are calibrated and compared against those of conventional steel specimens. Effect of varying axial force and loading direction on the hysteretic deterioration model, failure modes and axial shortening is also studied. Plate and tube elements in hybrid members interact such that the high strength steel is kept within its ultimate strain range to prevent sudden fracture due to its low ultimate to yield strain ratio while the ductile performance of plate governs the global failure mechanism. High strength material also significantly reduces the axial shortening in columns which prevents undesirable frame deformations.

Method using XFEM and SVR to predict the fatigue life of plate-like structures

  • Jiang, Zhansi;Xiang, Jiawei
    • Structural Engineering and Mechanics
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    • 제73권4호
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    • pp.455-462
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    • 2020
  • The hybrid method using the extended finite element method (XFEM) and the forward Euler approach is widely employed to predict the fatigue life of plate structures. Due to the accuracy of the forward Euler approach is determined by a small step size, the performance of fatigue life prediction of the hybrid method is not agreeable. Instead the forward Euler approach, a prediction method using midpoint method and support vector regression (SVR) is presented to evaluate the stress intensity factors (SIFs) and the fatigue life. Firstly, the XFEM is employed to calculate the SIFs with given crack sizes. Then use the history of SIFs as a function of either number of fatigue life cycles or crack sizes within the current cycle to build a prediction model. Finally, according to the prediction model predict the SIFs at different crack sizes or different cycles. Three numerical cases composed by a homogeneous plate with edge crack, a composite plate with edge crack and center crack are introduced to verify the performance of the proposed method. The results show that the proposed method enables large step sizes without sacrificing accuracy. The method is expected to predict the fatigue life of complex structures.

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.

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.

Buckling Analysis of Grid-Stiffened Composite Plates Using Hybrid Element with Drilling D.O.F.

  • Cho, Maenghyo;Kim, Won-Bae
    • Computational Structural Engineering : An International Journal
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    • 제3권1호
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    • pp.19-29
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    • 2003
  • In the present study, finite element linear buckling analysis is performed for grid-stiffened composite plates. A hybrid element with drilling degrees of freedom is employed to reduce the effect of the sensitivity of mesh distortion and to match the degrees of freedom between skins and stiffeners. The preliminary static stress distribution is analyzed for the determination of accurate load distribution. Parametric study of grid structures is performed and three types of buckling modes are observed. The maximum limit of buckling load was found at the local skin-buckling mode. In order to maximize buckling loads, stiffened panels need to be designed to be buckled in skin-buckling mode.

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Al 2024-T3 판에 AFRP를 접착한 복합재료의 인장강도에 대한 통계적 특성 (Statistical Properties for Tensile strength of Composite Materials Patched with AFRP on 2024-T3 Aluminum Alloy plate)

  • 윤한기;안원기;허선철
    • 대한기계학회논문집A
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    • 제24권7호
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    • pp.1810-1816
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    • 2000
  • A hybrid composite APAL(Aramid Patched Aluminum alloy) , consisting of Al 2024-T3 aluminum alloy plate sandwiched between two aramid/epoxy laminates, was developed. The characteristics of tensile s trength were investigated and statistical properties of tensile strength were studied in terms of Weibull distribution probability with number of AFRP laminates. The tensile strength of APAL was inproportional to number of AFRP laminates and followed the two-parametic Weibull distribution.

탄소섬유/에폭시 복합재료-알루미늄 양면겹치기 동시경화 조인트의 최적설계 (Optimal design of the co-cured aluminum/composite double lap joint)

  • 박상욱;김학성;이대길
    • 한국복합재료학회:학술대회논문집
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    • 한국복합재료학회 2004년도 추계학술발표대회 논문집
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    • pp.78-82
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    • 2004
  • The co-cured joint has been widely used in joining process of composite structures due to its simple and easy manufacturing process. In this paper, the effect of stacking sequence of the carbon epoxy prepreg, bonding length and thickness of the aluminum plate on the static tensile load capability of the co-cured aluminum-composite double lap joint were experimentally investigated. From experimental results, the optimum EA ratios with respect to stacking sequence and bonding length of the co-cured joint were obtained, which may be useful for the joining of hybrid structures.

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Optimum distribution of steel slit-friction hybrid dampers based on life cycle cost

  • Eldin, Mohamed Nour;Kim, Jaegoo;Kim, Jinkoo
    • Steel and Composite Structures
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    • 제27권5호
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    • pp.633-646
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    • 2018
  • This study investigated the seismic performance of a hybrid damper composed of a steel slit plate and friction pads, and an optimum retrofit scheme was developed based on life cycle cost. A sample hybrid damper was tested under cyclic loading to confirm its validity as a damping device and to construct its nonlinear analysis model. The effectiveness of the optimum damper distribution schemes was investigated by comparing the seismic fragility and the life cycle costs of the model structure before and after the retrofit. The test results showed that the damper behaved stably throughout the loading history. Numerical analysis results showed that the slit-friction hybrid dampers optimally distributed based on life cycle cost proved to be effective in minimizing the failure probability and the repair cost after earthquakes.

Stiffened orthotropic corner supported hypar shells: Effect of stiffener location, rise/span ratio and fiber orientaton on vibration behavior

  • Darilmaz, Kutlu
    • Steel and Composite Structures
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    • 제12권4호
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    • pp.275-289
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    • 2012
  • In this paper the influence of stiffener location, rise/span ratio and fibre orientation on vibration behavior of corner supported hypar shells is studied by using a four-node hybrid stress finite element. The formulation of the element is based on Hellinger-Reissner variational principle. The element is developed by combining a hybrid plane stress element and a hybrid plate element. Benchmark problems are solved to validate the approach and free vibration response of stiffened orthotropic hypar shells is studied both with respect to fundamental frequency and mode shapes by varying the location of stiffeners, rise/span ratio and fiber orientation.

Higher-order assumed stress quadrilateral element for the Mindlin plate bending problem

  • Li, Tan;Qi, Zhaohui;Ma, Xu;Chen, Wanji
    • Structural Engineering and Mechanics
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    • 제54권3호
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    • pp.393-417
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    • 2015
  • In this paper an 8-node quadrilateral assumed stress hybrid Mindlin plate element with $39{\beta}$ is presented. The formulation is based on complementary energy principle. The proposed element is free of shear locking and is capable of passing all the patch tests, especially the non-zero constant shear enhanced patch test. To accomplish this purpose, special attention is devoted to selecting boundary displacement interpolation and stress approximation in domain. The arbitrary order Timoshenko beam function is successfully used to derive the boundary displacement interpolation. According to the equilibrium equations, an appropriate stress approximation is rationally derived. Particularly, in order to improve element's accuracy, the assumed stress field is derived by employing $39{\beta}$ rather than conventional $21{\beta}$. The resulting element can be adopted to analyze both moderately thick and thin plates, and the convergence for the very thin case can be ensured theoretically. Excellent element performance is demonstrated by a wide of experimental evaluations.