Dynamic performance of low-rise steel frame with exposed steel column base

Abstract

The influence of changes in strength of exposed steel column bases (ESCBs) on the dynamic response of low-rise steel frames was studied by building on the theoretical sliding hysteresis curve model of ESCBs on the basis of a previous experimental study. The first-floor shear–weight ratio (CB = 0·30 and 0·35) and frame shape were taken into account in designing 16 strong-column/weak-beam regular low-rise steel frame models with the ratio of the strength of column bases to the strength of the first-floor column as the main study parameter. The results showed that when the strength coefficient of the steel column base was lower than 0·7, the model deformed at the first floor and plastic energy was concentrated if the first-floor shear–weight ratio was 0·30, while the first-floor deformation and plastic energy concentration of the model eased if the first-floor shear–weight ratio was 0·35. In addition, the lower the strength coefficient of the steel column base, the more obvious was the easing effect. The energy absorption of the column bases was not significant, but the column bases were able to transfer input seismic energy to other components during the plastic sliding process. The dynamic response hysteresis curves of the column bases matched the theoretical model well.