Effect of panel zone strength ratio on reduced beam section steel moment frame connections

Abstract

The effect of different panel zone design ratios (Rv/Vpz) on reduced-beam-section connections as part of steel moment resisting frames under cyclic and monotonic loading is investigated. As design specifications suggest an overestimated value for the (Rv/Vpz) ratio in some cases. To achieve this objective, the balanced design proposed in the specifications is compared to other design concepts in the guidelines. Then a finite element (FE) analysis is conducted representing the beam-to-column connection assemblies under cyclic and monotonic loading to investigate the effect of different panel zone strength ratios. The FE simulation is validated and compared to test results from the literature, then a parametric study is carried out. The parameters included in the study are; the column flange thickness, the panel zone aspect ratio, and the strong column weak beam ratio. Each connection configuration is investigated according to; the amount of energy dissipation achieved, the participation in energy dissipation between the beams and the panel zone, the stable hysteretic behavior and its fracture potential. Results from the analytical study show that for assemblies with thick column flanges the design specifications overestimate the panel zone strength. Therefore, a range for the validity of the panel zone design strength formula is suggested. Keywords: Panel zone, Reduced beam section, Beam-to-column connection