A STUDY OF ALLOWABLE STORY DRIFT AND Ds FACTOR OF HYBRID STRUCTURES WITH DIFFERENT RESTORING FORCE CHARACTERISTIC ELEMENT
Journal of Structural and Construction Engineering (Transactions of AIJ)
Ductility reduction factor Ds used in second phase design is based on the energy constant rule proposed by Newmark. In addition, it is also important to set a story drift limit to the structure on seismic design. Accordingly, allowable story drift and Ds factor are required to consider in design; however, the building code does not specifically address the relationship between these two values. The duration of the ground motion has less effect on the structure that has spindle-shaped response.
... e-shaped response. On the other hand, the structure having an origin progress slip response will cumulate the deformation during the seismic event; response deformation will increase lineally with the cycle of earthquake and f value. As a result, the relationship between allowable story drift and Ds factor for origin progress slip response structure should consider the characteristic of input ground motion. In this paper, firstly, Ds factor for the structure shows origin progress slip responses are discussed based on energy method and a formula for Ds factor based on cumulative plastic deformation ratio is proposed. Secondly, the relationship between allowable story drift and Ds factor for origin progress slip and the hybrid of origin progress slip and spindle-shaped responses are discussed. The results obtained from this research will make it possible to apply through dynamic analysis to second phase design uniformly. Finally, controversial point of current Ds formula is clarified from the comparison study between proposed Ds formula. Shigeharu YAGI, Toshikazu KARATSU, Atsushi SATO, Kikuo IKARASHI and Tetsurou ONO 73 628 999-1006 2008