Seismic displacements and behaviour factors assessment of an innovative steel and concrete hybrid coupled shear wall system

Abstract

The objective of this research is to facilitate the design process of innovative steel and concrete hybrid coupled wall system, which is obtained through the connection of a reinforced concrete (RC) wall to two steel side columns by means of steel links. To this end, a group of 120 innovative hybrid coupled wall systems subjected to a set of 100 far-field ground motions are selected. Thousands of nonlinear dynamic time histories on the basis of incremental dynamic analysis (IDA) are carried out in order to generate a databank of specified response quantities. Subsequently, nonlinear regression analyses are conducted in order to derive simple formulae which offer a direct estimation of: fundamental periods of vibration, seismic displacements, ductility demands and behaviour factors q for both designed and undesigned structures at different limit states; involving steel first yielding of internal wall, various predefined maximum inter-storey drifts and links rotations values. The effect of the following parameters: number of storeys, coupling ratio value, steel area ratio of boundary elements, uniformity status of shear links, and length of links is thoroughly investigated. The results indicate that storeys number and uniformity status parameters have the largest influence on the most of response quantities. The current q behaviour factor value is approximately suitable for low-rise building, but it is highly underestimated in medium-rise buildings. Furthermore, the equal-displacement rule clearly overestimates the roof ductility. Overall, this study bridges the gaps about the innovative hybrid coupled wall system design methodology and enables a rapid seismic assessment of such structures.