Design of cold-formed beam-columns restrained by sheeting

Kari Kolari, Asko Talja

    Research output: Book/ReportReport

    Abstract

    The load-bearing capacity and behaviour of laterally braced cold-formed sections has been studied in this project. The test program comprised 28 loading tests on cold-formed purlins continuously braced by trapezoidal sheeting and two tests where the purlins were connected to the gypsum board. The aim of the tests has been to determine the behaviour of single span purlin systems in combined compression and bending. The test program consists of centric and eccentric compression, bending with uplift and gravity load and combined compression and bending tests. A total of seven load cases for each of U-, C-, Z- and /sigma/-profiles were carried out. The test results are compared to design procedures determined by Eurocode 3 (1993), design of steel structures, draft annex A (part 1.3). The Eurocode 3 design method appears to give better results for C- and Z-profiles than for U- and /sigma/-profiles. It is also shown that the calculated ultimate loads according to Eurocode 3 are on average 62% conservative compared to tested results. The main reason for conservatism is in the effective length determination for the free flange. The fixed end boundary conditions used in VTT's tests are not included in the design expressions of Eurocode 3. The effective length for a beam on an elastic foundation with concentrated and distributed axial loading is derived using an energy method. The derived effective lengths are used with the Eurocode 3 design method. The use of correct effective lengths results in an average conservatism of 23 % in the design method. However, when the inelastic buckling of the free flange determines the ultimate load, the average conservatism is about 31%. The comparison is made between test and calculated characteristic resistance. Therefore the partial safety factor /gamma/M1 is set to 1.0. The accuracy of geometrically and materially non-linear finite element analysis of the /sigma/-profile is also verified. An example, where calculation of the C-profile according to Eurocode 3 is made, is included.
    Original languageEnglish
    Place of PublicationEspoo
    PublisherVTT Technical Research Centre of Finland
    Number of pages92
    ISBN (Print)951-38-4723-3
    Publication statusPublished - 1994
    MoE publication typeNot Eligible

    Publication series

    SeriesVTT Tiedotteita - Meddelanden - Research Notes
    Number1608
    ISSN1235-0605

    Fingerprint

    Flanges
    Safety factor
    Gypsum
    Bending tests
    Steel structures
    Bearing capacity
    Buckling
    Loads (forces)
    Gravitation
    Boundary conditions
    Finite element method

    Keywords

    • beams (supports)
    • columns (supports)
    • structural members
    • structural steels
    • steel construction
    • cold working
    • steel sheets
    • load-carrying capacity
    • loads (forces)
    • tests
    • calculations
    • design
    • behaviour
    • steel structures
    • compression tests
    • bending
    • comparison
    • structural flanges
    • finite element analysis

    Cite this

    Kolari, K., & Talja, A. (1994). Design of cold-formed beam-columns restrained by sheeting. Espoo: VTT Technical Research Centre of Finland. VTT Tiedotteita - Meddelanden - Research Notes, No. 1608
    Kolari, Kari ; Talja, Asko. / Design of cold-formed beam-columns restrained by sheeting. Espoo : VTT Technical Research Centre of Finland, 1994. 92 p. (VTT Tiedotteita - Meddelanden - Research Notes; No. 1608).
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    author = "Kari Kolari and Asko Talja",
    year = "1994",
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    Kolari, K & Talja, A 1994, Design of cold-formed beam-columns restrained by sheeting. VTT Tiedotteita - Meddelanden - Research Notes, no. 1608, VTT Technical Research Centre of Finland, Espoo.

    Design of cold-formed beam-columns restrained by sheeting. / Kolari, Kari; Talja, Asko.

    Espoo : VTT Technical Research Centre of Finland, 1994. 92 p. (VTT Tiedotteita - Meddelanden - Research Notes; No. 1608).

    Research output: Book/ReportReport

    TY - BOOK

    T1 - Design of cold-formed beam-columns restrained by sheeting

    AU - Kolari, Kari

    AU - Talja, Asko

    PY - 1994

    Y1 - 1994

    N2 - The load-bearing capacity and behaviour of laterally braced cold-formed sections has been studied in this project. The test program comprised 28 loading tests on cold-formed purlins continuously braced by trapezoidal sheeting and two tests where the purlins were connected to the gypsum board. The aim of the tests has been to determine the behaviour of single span purlin systems in combined compression and bending. The test program consists of centric and eccentric compression, bending with uplift and gravity load and combined compression and bending tests. A total of seven load cases for each of U-, C-, Z- and /sigma/-profiles were carried out. The test results are compared to design procedures determined by Eurocode 3 (1993), design of steel structures, draft annex A (part 1.3). The Eurocode 3 design method appears to give better results for C- and Z-profiles than for U- and /sigma/-profiles. It is also shown that the calculated ultimate loads according to Eurocode 3 are on average 62% conservative compared to tested results. The main reason for conservatism is in the effective length determination for the free flange. The fixed end boundary conditions used in VTT's tests are not included in the design expressions of Eurocode 3. The effective length for a beam on an elastic foundation with concentrated and distributed axial loading is derived using an energy method. The derived effective lengths are used with the Eurocode 3 design method. The use of correct effective lengths results in an average conservatism of 23 % in the design method. However, when the inelastic buckling of the free flange determines the ultimate load, the average conservatism is about 31%. The comparison is made between test and calculated characteristic resistance. Therefore the partial safety factor /gamma/M1 is set to 1.0. The accuracy of geometrically and materially non-linear finite element analysis of the /sigma/-profile is also verified. An example, where calculation of the C-profile according to Eurocode 3 is made, is included.

    AB - The load-bearing capacity and behaviour of laterally braced cold-formed sections has been studied in this project. The test program comprised 28 loading tests on cold-formed purlins continuously braced by trapezoidal sheeting and two tests where the purlins were connected to the gypsum board. The aim of the tests has been to determine the behaviour of single span purlin systems in combined compression and bending. The test program consists of centric and eccentric compression, bending with uplift and gravity load and combined compression and bending tests. A total of seven load cases for each of U-, C-, Z- and /sigma/-profiles were carried out. The test results are compared to design procedures determined by Eurocode 3 (1993), design of steel structures, draft annex A (part 1.3). The Eurocode 3 design method appears to give better results for C- and Z-profiles than for U- and /sigma/-profiles. It is also shown that the calculated ultimate loads according to Eurocode 3 are on average 62% conservative compared to tested results. The main reason for conservatism is in the effective length determination for the free flange. The fixed end boundary conditions used in VTT's tests are not included in the design expressions of Eurocode 3. The effective length for a beam on an elastic foundation with concentrated and distributed axial loading is derived using an energy method. The derived effective lengths are used with the Eurocode 3 design method. The use of correct effective lengths results in an average conservatism of 23 % in the design method. However, when the inelastic buckling of the free flange determines the ultimate load, the average conservatism is about 31%. The comparison is made between test and calculated characteristic resistance. Therefore the partial safety factor /gamma/M1 is set to 1.0. The accuracy of geometrically and materially non-linear finite element analysis of the /sigma/-profile is also verified. An example, where calculation of the C-profile according to Eurocode 3 is made, is included.

    KW - beams (supports)

    KW - columns (supports)

    KW - structural members

    KW - structural steels

    KW - steel construction

    KW - cold working

    KW - steel sheets

    KW - load-carrying capacity

    KW - loads (forces)

    KW - tests

    KW - calculations

    KW - design

    KW - behaviour

    KW - steel structures

    KW - compression tests

    KW - bending

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    KW - structural flanges

    KW - finite element analysis

    M3 - Report

    SN - 951-38-4723-3

    T3 - VTT Tiedotteita - Meddelanden - Research Notes

    BT - Design of cold-formed beam-columns restrained by sheeting

    PB - VTT Technical Research Centre of Finland

    CY - Espoo

    ER -

    Kolari K, Talja A. Design of cold-formed beam-columns restrained by sheeting. Espoo: VTT Technical Research Centre of Finland, 1994. 92 p. (VTT Tiedotteita - Meddelanden - Research Notes; No. 1608).