Comparison of ductility reduction factors for MDOF flexure-type and shear-type systems

This research investigates the difference of seismic ductility reduction factors between flexure-type and shear-type multi-degree-freedom (MDOF) systems. Multi-mass column cantilever systems are employed to simulate flexure-type shear-wall structure, while multi-mass series spring connection systems are used to simulate shear-type frame structure. Four earthquake records in hard soil site are employed to conduct nonlinear dynamic time history analysis. The effects of storey displacement ductility and vibration period on the seismic ductility reduction factors for flexure-type structure are studied, and the ductility reduction factors between flexure-type and shear-type structures are compared. The results show that the ductility reduction factors for flexure-type structure are about 40 % larger than those for flexure-type structure. Meanwhile, storey displacement ductility and storey number are important factors on seismic ductility reduction factors.