Beam Tests with Unreinforced Web Openings

Experimental results are presented showing the effect on ultimate moment capacity at sections of a wide-flange beam weakened by large web openings. Parameters investigated include the opening shape, the ratio of moment to shear at the openings, and the effect of adjacent openings at various spacings. Tests were carried out on 8WF17 beams with circular, rectangular and flat sided openings with semicircular ends. The results show that large reductions in capacity can occur and that these increase with the amount of shear present. An identical adjacent opening does not have much influence on the strength of a circular opening, but significant reductions in strength of a rectangular opening can be produced by a second opening.