Application of finite element method and photoelasticity to an lap welded connection

  • G.L. Hilborne

    Student thesis: Master's ThesisMaster of Philosophy


    The stress distribution in the plates of lap fillet welded
    connections is known to be non-uniform. In order to examine
    the stress distribution in the plates of a double-cover-
    Strap joint with fillet welds, a theoretical model of the
    joint was analysed using the Finite Element method of
    analysis. Photo-Elastic model tests were carried out to
    confirm the assumptions made in the analytical model. An
    understanding of the Finite Element method of analysis was
    obtained by applying this method manually to the solution
    of a single plate under uniform and parabolic tensile
    loading. A lap weld connection with a very coarse mesh was
    then examined manually in order to determine the most
    appropriate method of element and joint numbering. Using a
    computer programme an analytical model of a side fillet
    welded connection having equal thickness cover plates and
    main plate was analysed by the Finite Element method. The
    effect of varying the relative thickness of the cover and
    main plate was examined, together with the effect of cutting
    a hole in the cover plate and welding the cover plate all
    round. Photo-Elastic models were made for the side fillet
    welded and the welded all round cover plate cases. The stresses
    were frozen into the models and after separation of the
    Joint each plate was analysed in a photo-elastic bench,
    ‘Graphs and pictorial plots were made to compare the Finite
    Element and Photo-Elastic results. The pictorial plots
    clearly show that the stress distribution in the plates
    for the welded all round case is far superior to the side
    fillet welded case. Results obtained by varying the relative
    thickness of cover and main plate indicate that the best
    joint, is obtained by using a main plate thickness of half
    the thickness of each cover plate, and welding the cover
    plates all round.

    To determine the most efficient joint, further work is
    required to obtain the best weld length for optimum plate
    and weld stresses.
    Date of Award1973
    Original languageEnglish


    • Application
    • finite element method
    • photo-elasticity
    • welded connection

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