Net Section Failure of S690 High-Strength Steel Angle-to-Plate Connections

Abstract

The net section fracture behavior and resistance of S690 high-strength steel angle-to-plate connections were investigated in this paper, underpinned by testing and numerical modeling. The experiments were conducted on 23 S690 high-strength steel angle-to-plate connections, with each comprising an equal- or unequal-leg press-braked angle section member bolted to gusset plates by one leg. The test procedures and setup and the key observed results were fully presented and analyzed. The experimental program was supplemented by a numerical modeling program with which finite element models were first developed and validated against the experimental responses and afterward adopted to perform parametric studies to produce additional numerical data. Based on the test and numerical data, the codified design rules for S690 high-strength steel angle-to-plate connections with net section fracture were evaluated. The results of the evaluation revealed that (1) the American specification leads to consistent but unsafe failure load predictions, (2) the European code yields conservative and scattered failure load predictions, and (3) the Australian standard results in scattered, though accurate on average, predictions of failure load, and many of the predicted failure loads are unsafe. Finally, a new design method was proposed and shown to offer substantially improved failure load predictions for S690 high-strength steel angle-to-plate connections over the design codes.