<title>Study on applicability of rocking structural systems to building structures</title>

Abstract

We are now developing the rocking structural system that can reduce earthquake responses of building structures by causing rocking vibration on them under appropriate control. This paper examines applicability of this system to building structures based on case studies using four realistic steal planer frame models which have 5 stories and 1 bay. All models have the same height and width, which are 18 m and 6 m respectively. But they have the different first natural period. These values range from 0.384 s to 0.729 s. The case studies are executed using a numerical simulation method. Furthermore, we propose simple prediction method for earthquake responses of the rocking structural systems using the equivalent one mass model. It is concluded that the rocking structural systems can reduce seismic responses of building structures effectively, and these response values can be predicted by the proposed method appropriately.

Seismic performance of hybrid ductile‐rocking braced frame system

“…Additional system stiffness due to beam-column connection stiffness, continuous gravity columns, and other sources of stiffness that are not considered in the code-based seismic design were not incorporated into these simplified models. Three zero-length elements were placed in parallel in order to model the gap after uplift, the lock-up, and the energy dissipation elements, in a similar manner to the numerical model of the yielding base plates in Azuhata et al 11 The energy dissipation elements were modeled using an elastoplastic material. Thus, the models presented in this paper represent a conservative method for determining frame deformations.…”

“…11,33 A variety of different modeling techniques were used in these references, and further discussion of vertical mass modeling, beyond the simple lumped-mass technique used in the parametric study, is warranted. This amplification was hypothesized to be the result of the excitation of vertical mass in the numerical models, and thus a side study was performed in order to determine the effect of different vertical mass modeling choices on the results.…”

“…For these models, the gravity elements for the bays to the right and left of the SFRS were modeled (these elements are the same as those outlined in Binder 23 using elastic beam-column elements). M2 uses the modeling scenario described in Azuhata et al 11 M3 places the mass at the beams eighth points, similar to Midorikawa et al 13 Finally, M4 completely neglects the vertical mass, as is typically done in conventional numerical analyses. M1 ( Figure 13A) lumps the tributary mass at the beam-column connections, which is the modeling choice that was used in the parametric study in Section 5.…”

“…One node was fully fixed, and the other was free to uplift but restrained in the horizontal direction in order to transfer base shear. Three zero-length elements were placed in parallel in order to model the gap after uplift, the lock-up, and the energy dissipation elements, in a similar manner to the numerical model of the yielding base plates in Azuhata et al 11 The energy dissipation elements were modeled using an elastoplastic material. The compression-only element (also referred to here as the "contact" element) was modeled with a large compressive stiffness and no stiffness in tension.…”

“…In the early 2000s, this concept was investigated by Japanese researchers who developed yielding column connections and base plates that permitted column uplift in steel frame structures. [10][11][12][13] Rocking concepts have more recently been used in high performance controlled rocking (CR) structures by a number of researchers who used post-tensioning elements in conjunction with supplemental energy dissipation elements to control rocking strength and post-rocking stiffness, and achieve systems that preclude residual deformations and structural damage. [14][15][16][17] While CR frames are promising low-damage systems, they have drawbacks related to their dynamic response and practical implementation.…”