Meshless local buckling analysis of steel beams with irregular web openings

In addition to typical perforated beams with regular openings of circular or hexagonal holes, the use of beams with irregular web holes of different shapes and arrangement is also widespread in steel construction. Despite some advantages over typical perforated beams, the behaviour of such beams is complicated by the irregularity of openings, which demands more reliable tools for assessing their local buckling response. This paper considers the efficient local buckling analysis of beams with regular and irregular web openings, employing the Element Free Galerkin (EFG) method for the numerical discretisation together with a simplified buckling assessment approach from the Rotational Spring Analogy (RSA). This combination offers a more effective means of buckling assessment utilising an iterative procedure of a rank 2 reduced eigenvalue problem along with a shifting local region. Several illustrative examples are provided to demonstrate the effectiveness of the proposed EFG/RSA approach for local buckling analysis of steel beams with irregular openings.

► Local buckling analysis via uncoupled planar/out-of-plane response and shifted local region.
► Formulation of unit cell response and discrete assembly for overall system response.
► Element Free Galerkin method and Rotational Spring Analogy for material and geometric stiffness.
► Buckling prediction in shifted region via reduced rank 2 iterative eigenvalue analysis.
► Favourable comparison against nonlinear FEA for several typical examples of perforated beams.