The Experts below are selected from a list of 177 Experts worldwide ranked by ideXlab platform

Y.-x. Zhang - One of the best experts on this subject based on the ideXlab platform.

  • strength enhancement of high strength steel beams by engineered cementitious composites encasement
    Engineering Structures, 2020
    Co-Authors: Md Imran Kabir, Mohammad M Rana, Y.-x. Zhang
    Abstract:

    Abstract This study proposes a method of using Polyvinyl Alcohol Engineered Cementitious Composites (PVA-ECC) encasement to provide continuous restraints along the Compression Flange of High Strength Steel (HSS) section so that it will reach its sectional plastic moment resistance under bending without lateral restraint. In order to demonstrate the effectiveness of the proposed method, experimental and numerical investigations were carried out to study the flexural strength of the ECC encased HSS beams (ECC-HSS beams). Six simply supported beams fabricated with identical HSS sections but with different encasement configurations were tested until failure. Flexural resistance and failure modes of the ECC-HSS beams were compared with similar bare HSS and normal concrete (NC) encased HSS beams (NC-HSS beams). It was found that when compared with the bare HSS and NC-HSS beams, a significant enhancement in flexural resistance was achieved for the ECC-HSS beams. More importantly, this study confirmed that the compressive ECC layers was crushed after the Compression Flanges were yielded and therefore successfully prevented the onset of lateral torsional buckling. Besides the flexural responses, the interfacial slip behaviours along the Compression Flange of the HSS section were also studied. Finally, a finite element (FE) model was developed and validated against the experimental results.

  • flexural and bond slip behaviours of engineered cementitious composites encased steel composite beams
    Journal of Constructional Steel Research, 2019
    Co-Authors: Md Imran Kabir, Mohammad M Rana, C K Lee, Y.-x. Zhang
    Abstract:

    Abstract This paper studies the flexural and bond-slip behaviour of composite beams fabricated by encasing universal steel beams with Polyvinyl Alcohol-Engineered Cementitious Composite (PVA-ECC) and Light Weight Concrete (LWC). Four-point bending tests were conducted on one bare steel and four composite beams with different ECC and LWC encasement configurations. Test results showed that the ECC and LWC encasements could enhance the flexural strength and ductility of bare steel beams significantly. Furthermore, it was found that the weight of the encased beams could be further reduced by either replacing the bottom ECC layer with LWC or even only encasing the Compression Flange of the steel section without reducing the flexural strength of the beam significantly. The bond-slip behaviour between the ECC matrix and the steel section was also investigated. The experimental study is complemented by a non-linear finite element (FE) model which was validated against the test results. A small scale parametric study was then conducted by using the validated FE model to investigate the performances of beams formed by the steel sections with yield strengths ranging from 350 MPa to 960 MPa.

  • Flexural and bond-slip behaviours of engineered cementitious composites encased steel composite beams
    'Elsevier BV', 2019
    Co-Authors: Mi Kabir, C K Lee, Mm Rana, Y.-x. Zhang
    Abstract:

    © 2019 Elsevier Ltd This paper studies the flexural and bond-slip behaviour of composite beams fabricated by encasing universal steel beams with Polyvinyl Alcohol-Engineered Cementitious Composite (PVA-ECC) and Light Weight Concrete (LWC). Four-point bending tests were conducted on one bare steel and four composite beams with different ECC and LWC encasement configurations. Test results showed that the ECC and LWC encasements could enhance the flexural strength and ductility of bare steel beams significantly. Furthermore, it was found that the weight of the encased beams could be further reduced by either replacing the bottom ECC layer with LWC or even only encasing the Compression Flange of the steel section without reducing the flexural strength of the beam significantly. The bond-slip behaviour between the ECC matrix and the steel section was also investigated. The experimental study is complemented by a non-linear finite element (FE) model which was validated against the test results. A small scale parametric study was then conducted by using the validated FE model to investigate the performances of beams formed by the steel sections with yield strengths ranging from 350 MPa to 960 MPa

Elizabeth M Ford - One of the best experts on this subject based on the ideXlab platform.

  • stiffness requirements for longitudinally stiffened box girder Flanges
    Journal of Structural Engineering-asce, 2001
    Co-Authors: Byung H Choi, Elizabeth M Ford
    Abstract:

    This paper presents an optimum design of longitudinal stiffeners for box-girder Compression Flanges. The buckling behavior of longitudinally stiffened Compression Flanges has drawn considerable interest from early pioneers of theoretical mechanics, as illustrated by Timoshenko and Gere, and Bleich. The longitudinally stiffened Compression plate structural members generally render an economical structure by efficiently proportioning the material to resist the induced compressive stresses. This study presents results that are based on 3D finite-element analyses of several hundred hypothetical Compression Flange models stiffened by varying numbers of longitudinal stiffeners with realistic dimensions. The thickness of the Compression Flange \it was varied from 0.50 to 2.50 in. (from 12.7 to 63.5 mm); the number of longitudinal stiffeners \in was varied from 1 to 4; and the aspect ratio of the plate panel \Iα\N was varied from 1 to 5. Two different plate transverse slenderness ratios \Iw/t\N were analyzed. Analytical data were reduced using nonlinear regression analysis to a simplified design equation suitable for practicing engineers. Several example problems are given to illustrate the use of the regression equation. Comparative analyses are also made to demonstrate the versatility and reliability of the analytical study conducted.

Ahmer M Wadee - One of the best experts on this subject based on the ideXlab platform.

  • interactively induced localization in thin walled i section struts buckling about the strong axis
    Structures, 2015
    Co-Authors: Elizabeth L Liu, Ahmer M Wadee
    Abstract:

    Abstract A variational model describing the behaviour of a thin-walled I-section strut suffering from local–global buckling mode interaction is presented where global (Euler) buckling about the strong axis is the critical mode. A system of differential and integral equations is derived that describe the equilibrium states from variational principles and are solved numerically using the continuation and bifurcation software A uto -07 p for the perfect case. Initially stress relieved out-of-straightness imperfections are subsequently introduced and the nonlinear response is modelled. The modelled interaction is between the critical global buckling mode about the strong axis and local buckling in the Flange and web simultaneously, where the Flange–web joint is assumed to be free to rotate as a rigid body. The initial eigenmode is shown to be destabilized at a secondary bifurcation where interactive buckling is triggered. A progressive change in the buckling mode is then observed, initially with local buckling localizing at the mid-span of the Compression Flange, which also triggers sympathetic local buckling in the web. The results from the analytical model have been validated using the commercial finite element (FE) software A baqus with good comparisons presented for the initial post-buckling behaviour. The strut also exhibits sensitivity to initial out-of-straightness imperfections, with a notable decrease in the ultimate load as the imperfection size increases. The ultimate loads for a range of imperfection amplitudes are found using both analytical models and FE analysis, with very good correlation observed.

Akhil Upadhyay - One of the best experts on this subject based on the ideXlab platform.

  • global buckling behavior of blade stiffened Compression Flange of frp box beams
    Structures, 2021
    Co-Authors: M Kasiviswanathan, Akhil Upadhyay
    Abstract:

    Abstract Light weight superstructure is beneficial for bridges in remote areas and in emergency erection. In such weight sensitive applications, combination of fiber reinforced polymer (FRP) as a material and stiffened box-beams as a structural system have great scope. This combination offers various advantageous but being a thin walled structure, their designs are often governed by buckling criteria. In the case of longitudinally stiffened box-beams, stiffened panels predominately loss their stability either by local or global buckling mode. In this paper, global buckling behavior of the stiffened panel is studied as part of the box-beam to take care the effect of realistic state of stress in the Compression Flange and effect of boundary condition at web-Flange junctions. A parametric study by varying the sectional geometry and fiber orientation is carried out by using ANSYS software. The accuracy of the FE models was ensured by verifying them against the available results provided in the literature. With the help of developed database, the influential parameters (i.e. D1/D2, (EA)fs/(EA)fp, αsf, CEIw and βsf) affecting the global bucklings are identified. The significance on buckling stress is shown with the help of generic curves and bar charts which will be helpful to the designers at the preliminary stage.

Md Imran Kabir - One of the best experts on this subject based on the ideXlab platform.

  • strength enhancement of high strength steel beams by engineered cementitious composites encasement
    Engineering Structures, 2020
    Co-Authors: Md Imran Kabir, Mohammad M Rana, Y.-x. Zhang
    Abstract:

    Abstract This study proposes a method of using Polyvinyl Alcohol Engineered Cementitious Composites (PVA-ECC) encasement to provide continuous restraints along the Compression Flange of High Strength Steel (HSS) section so that it will reach its sectional plastic moment resistance under bending without lateral restraint. In order to demonstrate the effectiveness of the proposed method, experimental and numerical investigations were carried out to study the flexural strength of the ECC encased HSS beams (ECC-HSS beams). Six simply supported beams fabricated with identical HSS sections but with different encasement configurations were tested until failure. Flexural resistance and failure modes of the ECC-HSS beams were compared with similar bare HSS and normal concrete (NC) encased HSS beams (NC-HSS beams). It was found that when compared with the bare HSS and NC-HSS beams, a significant enhancement in flexural resistance was achieved for the ECC-HSS beams. More importantly, this study confirmed that the compressive ECC layers was crushed after the Compression Flanges were yielded and therefore successfully prevented the onset of lateral torsional buckling. Besides the flexural responses, the interfacial slip behaviours along the Compression Flange of the HSS section were also studied. Finally, a finite element (FE) model was developed and validated against the experimental results.

  • flexural and bond slip behaviours of engineered cementitious composites encased steel composite beams
    Journal of Constructional Steel Research, 2019
    Co-Authors: Md Imran Kabir, Mohammad M Rana, C K Lee, Y.-x. Zhang
    Abstract:

    Abstract This paper studies the flexural and bond-slip behaviour of composite beams fabricated by encasing universal steel beams with Polyvinyl Alcohol-Engineered Cementitious Composite (PVA-ECC) and Light Weight Concrete (LWC). Four-point bending tests were conducted on one bare steel and four composite beams with different ECC and LWC encasement configurations. Test results showed that the ECC and LWC encasements could enhance the flexural strength and ductility of bare steel beams significantly. Furthermore, it was found that the weight of the encased beams could be further reduced by either replacing the bottom ECC layer with LWC or even only encasing the Compression Flange of the steel section without reducing the flexural strength of the beam significantly. The bond-slip behaviour between the ECC matrix and the steel section was also investigated. The experimental study is complemented by a non-linear finite element (FE) model which was validated against the test results. A small scale parametric study was then conducted by using the validated FE model to investigate the performances of beams formed by the steel sections with yield strengths ranging from 350 MPa to 960 MPa.