10 results for Peng, B.H.H.

  • Experimental study on the seismic performance of RC moment resisting frames with precast-prestressed floor units

    Peng, B.H.H.; Fenwick, R. C.; Dhakal, R.P.; Bull, D.K. (2008)

    Conference Contributions - Published
    University of Canterbury Library

    Paper No.37

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  • Evaluation of Lay's equation for plastic hinge location in steel columns

    Peng, B.H.H.; MacRae, G.A.; Walpole, W.R.; Moss, P.J.; Dhakal, R.P.; Clifton, C.; Hyland, C. (2007)

    Conference Contributions - Published
    University of Canterbury Library

    The current New Zealand steel structures standard has a provision that aims to restrict plastic hinges to develop only at the member ends. The equations in this provision were adopted from Lay’s PhD thesis which were developed not only to encourage yielding at the member end, but also to ensure sufficient member rotational capacity can be maintained. The accuracy of the end yielding criteria in Lay’s equations is examined using an analytical technique developed in this study. The analytical procedure incorporates nonlinear geometric and material effects by considering stability functions in conjunction with residual stress effects. It is found that the code equations are more conservative compared with the analysis results. A new equation to prevent yielding away from the member ends is proposed in the research project. This forms the basis for the proposed amendments to Clause 8.4.3.2 in New Zealand steel structures standard.

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  • Location of Plastic Hinges in Columns of Steel Frames

    Peng, B.H.H.; MacRae, G.; Walpole, W.; Moss, P.J.; Dhakal, R.P.; Clifton, C. (2007)

    Conference Contributions - Published
    University of Canterbury Library

    The New Zealand Steel Structures Standard has a seismic provision aiming to ensure that plastic hinges occur at the ends of steel columns rather than along their length. This provision often governs the column sizes in steel frames and concerns have been raised about the need for this requirement and the accuracy of the equation in the provision. This paper describes research carried out to evaluate this equation. Methods were developed from first principles considering second order and residual stress effects. Time history analysis was carried out with RUAUMOKO to examine the likelihood of plastic hinges forming away from the column ends. A computer program was also used to examine the applicability of this equation on different types of steel frame. A new equation is proposed based on the analytical results. It is found that the provision is not applicable to columns in the majority of moment-resisting frames. Columns in eccentrically braced frames, designed in accordance with the capacity design philosophy, often did not yield even at the column base during earthquake excitations. A simple check is proposed to determine whether yielding would occur under a design drift limit which can be used in conjunction with the proposed equation.

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  • Experimental Investigation on the Interaction of Reinforced Concrete Frames with Precast-Prestressed Concrete Floor Systems

    Peng, B.H.H.; Dhakal, R.P.; Fenwick, R.C.; Carr, A.J.; Bull, D.K. (2008)

    Conference Contributions - Published
    University of Canterbury Library

    http://www.14wcee.org/Proceedings/isv7/main.htm Paper ID: 12-01-0042

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  • Analytical model of ductile reinforced concrete frames allowing for elongation of plastic hinges

    Peng, B.H.H.; Dhakal, R.P.; Fenwick, R.C.; Carr, A.J.; Bull, D.K. (2008)

    Conference Contributions - Other
    University of Canterbury Library

    Elongation in reinforced concrete members can have detrimental effect on the seismic performance of reinforced concrete structures. For reliable assessment of seismic performance, analytical models should take into account this elongation phenomenon. In this paper, an analytical model of plastic hinges has been developed and implemented into an analysis package. This model consists of a layer of horizontal concrete and steel springs to simulate the flexural behavior, as well as diagonal springs to represent the diagonal compression struts and to resist the shear force. The model is verified against experimental results of beams and frame subassembly tests found in literature. Comparisons of the analytical predictions and the experimental results show that this model can make significant advancement in predicting elongation in beam plastic hinges. It can be used to assess the effect of beam elongation on the seismic performance of reinforced concrete frame structures.

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  • Effect of precast-prestressed flooring systems on the seismic performance of reinforced concrete frames

    Peng, B.H.H.; Dhakal, R.P.; Fenwick, R.C. (2008)

    Conference Contributions - Other
    University of Canterbury Library

    A one story, two bays, approximately half scaled, perimeter moment frame containing precastprestressed floor units was built and tested at the University of Canterbury to investigate the effect of precastprestressed floor units on the seismic performance of reinforced concrete moment resisting frame. This paper gives an overview of the experimental set up and summarizes the results obtained from the test. The results show that elongation in the beam plastic hinges is partially restrained by the prestressed floor, which increases the strength of the beams much more than that being specified in the codes around the world.

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  • Location of Plastic Hinges in Axially Loaded Steel Members

    Peng, B.H.H.; MacRae, G.A.; Walpole, W.R.; Moss, P.; Dhakal, R.P.; Hyland, C.; Clifton, C. (2008)

    Journal Articles
    University of Canterbury Library

    New Zealand and Australian steel structure design standards contain equations to encourage yielding at the ends of steel members rather than along their lengths. This paper evaluates the accuracy of these equations using a commercially available computer program as well as an analytical procedure. The analytical procedure considers non-linear geometric effects and material effects of the member stiffness by considering stability functions in conjunction with residual stress effects. New equations to prevent yielding away from the member ends, which are less conservative than the current code equations, are developed. Simplifications of these equations being considered for adoption into the New Zealand steel structure design standard are described.

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  • Flexural, axial load and elongation response of plastic hinges in reinforced concrete member

    Peng, B.H.H.; Dhakal, R.P.; Fenwick, R.C.; Carr, A.J.; Bull, D.K. (2007)

    Conference Contributions - Published
    University of Canterbury Library

    Previous research in New Zealand has indicated that elongation of plastic hinges in reinforced concrete (RC) beams can have a significant effect on the seismic performance of RC structures. A number of empirical formulas have been proposed to predict elongation. However, no satisfactory analytical models are currently available which can be used to predict the influence of elongation on the seismic performance. This paper describes a plastic hinge model developed to predict the combined flexural, axial load and elongation response of plastic hinges in RC beam. The model is a filament type element which consists of layers of longitudinal and diagonal axial springs to represent the flexural, shear and elongation response of a plastic hinge. Analytical predictions for beams with different levels of axial load are compared with the experimental results. It is found that the plastic hinge model predicts the response satisfactorily. With this newly formed element, seismic analyses may be performed to assess the significance of beam elongation on seismic performance of RC structures.

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  • Seismic performance of reinforced concrete frames with precast prestressed flooring system

    Peng, B.H.H.; Fenwick, R.C.; Dhakal, R.P.; Carr, A.J. (2009)


    University of Canterbury Library

    In a current research project the influence that floor slabs containing precast prestressed units have on the seismic performance of plastic hinges in beams of moment resisting frames is being examined. A three dimensional, approximately half scale, one storey, two bay moment resisting frame together with adjacent floor slab has been constructed and tested. The experimental results show that the building code, ACI 318-05, underestimates the flexural strength of beams by a considerable margin. An analytical model has been developed which predicts the flexural, shear and elongation response of plastic hinges in beams subjected to inelastic rotation history and varying axial load levels. This model can be used to predict the interaction between beams in moment resisting frames and floor slabs containing precast prestressed units. Analysis using this model shows good agreement with the experimental results.

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  • Plastic hinge location in columns of steel frames subjected to seismic actions

    Peng, B.H.H.; MacRae, G.A.; Walpole, W.R.; Moss, P.; Dhakal, R.P.; Clifton, C. (2008)

    Journal Articles
    University of Canterbury Library

    Several steel structure standards around the world contain an equation to encourage any column flexural yielding during earthquake shaking to occur at the column ends, rather than along the column length. The accuracy of these equations and their applicability to columns of both moment frames and braced frames are examined in this paper. It is shown, using an analytical procedure developed from first principles considering the reduction in member stiffness from axial force due to geometric and material nonlinearity, that the existing code equations are conservative. Less conservative empirical equations are developed based on the analysis results. It is found that these equations are applicable to frames with a braced connection, rather than a moment connection into the column. Time-history analysis of eccentrically-braced frames with inverted V-bracing, where the active link occurs at the centre of the beam, is carried out. The likely column end moment ratio needed for the new equations is determined. The analysis also shows that yielding often did not occur in the bottom story columns during earthquake excitations. A simple check is proposed to relate the axial force limit and the design drift to flexural yielding of columns which can be used in conjunction with the proposed equations

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