Design of steel beams with end copes

Abstract

Abstract In steel beams with end copes, the strength and torsional stiffness at the coped section are reduced and a high stress concentration in the web at the cope corner is introduced. Therefore, besides yielding, coped beams can fail in three distinct failure modes: lateral-torsional buckling, local web buckling and fatigue cracking. Based on the behavior and analytical studies of coped beams, design methods are proposed for these three failure modes. Simple interaction equations, which utilize the individual lateral buckling capacities of the coped region and the uncoped length, are developed for design of the lateral buckling of coped beams. Inelastic lateral buckling caused by the residual stresses and design of short span coped beams are also considered. As for local buckling strength at the coped region, a plate buckling model is developed for compression flange coped beams, and a lateral buckling model is adopted for double flange coped beams. Yielding at the coped corner caused by the high local stress concentration is considered in the design. For the fatigue strength of coped beams, the actual stress range, which is the nominal stress range multiplied by the stress concentration factor, could be used along with the category C from the existing S-N curves when one is designing coped beams subjected to fatigue loading.