Tensile Rupture of Rectangular Hollow Section Flexural Members with Holes in the Tension Flange

Abstract

An evaluation of the AISC Specification Section F13.1 provisions for the reduction in strength of beams and girders with holes in the tension flange is performed. Twelve simply supported rectangular hollow section (RHS)-to-RHS splice connections with variations in RHS shape, number of bolts, and bolting arrangement are tested under monotonic four-point bending, and net-section rupture (in the tension flange) is achieved. The results demonstrate that, for RHS members, the current AISC Specification Section F13.1 provisions are vastly conservative. The current results are combined with the previous data from 138 tests on wide-flange girders with holes in the tension flange, and a new nominal flexural strength (M_n) equation is developed using net section properties. The new equation is shown to increase the accuracy of M_n predictions and reduce scatter in the predicted results. A reliability analysis is performed to demonstrate that the new approach provides acceptable levels of reliability when compared to the target reliability index of 4.0 specified in Chapter B of the Specification commentary.