Cyclic testing of beam-to-column connections with weld defects and assessment of safety of numerically modeled connections from brittle fracture

This paper concerns the assessment of significance of weld defects in beam-to-column connections. Four full-sized beam-to-column connections with weld defects were tested under cyclic loads. When the unfused regions created by partial joint penetration groove welds were reinforced by fillet welds so that the welded joints have a sufficient cross-sectional area, ductile cracks grew stably and, in consequence, the connections showed sufficient deformation capacity. The connections with weld defects at the root of welds sustained a quick extension of ductile cracks and, eventually, failed by brittle fracture. Test results were reproduced well by non-linear FE analyses. Fracture toughness properties of numerically modeled weld defects were evaluated by using a recently developed fracture mechanics approach. The results of evaluation were found to correspond well with test results.