Optimal lateral aseismic performance analysis of mega‐substructure system with modularized secondary structures

Abstract

Summary A major type of mega‐substructure system is yet to fulfill its full potential of vibration control because of the fragility originating from excessive inter‐story drift of its secondary structures during earthquake. We propose an innovative subtype of mega‐substructure system to overcome this fragility and further improve its lateral aseismic performance. This subtype takes advantage of modular construction techniques. The secondary structures, which consist of suspended discrete modules, provide protection to nonstructural members against excessive inter‐story drift. Additionally, springs that provide inter‐story stiffness remain elastic. These effects extend the inter‐story drift limit of secondary structure and make sufficient relative motion possible. We carried out single‐objective and dual‐objective optimizations to derive optimum parameters and capture the potentials of representative models. Mean square responses under power spectral density functions of ground acceleration were set as optimization objectives. It is shown that the proposed systems further suppress the response of primary structure at the expense of additional response of secondary structure, which can be accommodated by the aforementioned protection effect. Mechanisms are revealed in the perspective of transfer function curves. Robustness and time history performances are also verified.

Cross‐level fragility analysis of modularized suspended buildings based on experimentally validated numerical models

“…The previously proposed modularized suspended building structure [5] is presented in Figure 1a. A reinforced concrete core-tube with a steel truss on the top is the primary part of the system.…”

“…It has been revealed by Ye et al [5,14] that the protection effect of suspended modules loosens the inter-module drift limit and allows sufficient relative motion between the primary and secondary structures for the optimal seismic control. Moreover, the discretization of the suspended segment leads to the following effect.…”

“…In order to overcome such vulnerability, a modularized suspended building system (MSBS) was proposed. [5] A chain of pin-connected prefabricated 3D modules [11][12][13] is suspended from a transfer truss on top of an RC core structure (Figure 1a). Within the suspended segment, inter-story drifts consist mainly of the relative rigid-body motion between the upper and lower modules.…”

A Study on Nonlinear Dynamic Response of the Large-Span Roof Structure with Suspended Substructure

“…Tatemichi et al [6] investigated the behavior of suspended floor slabs using hangar rods in high-rise structures, both analytically and experimentally, for the purpose of seismic isolation. Ye et al [7,8] applied the suspended floor in modular building, studied its dynamic response both numerically and experimentally, and optimized the structure to verify its robustness and aseismic performance. It is to be noted that the aforementioned studies focus mainly on horizontal vibration mitigation, while the literature deals rarely with the vertical performance of suspended structures and their application in large-span roof structures.…”

“…Chulahwat and Mahmoud [3,18] explored the dynamic response of a steel frame with a suspended floor, with hanger rods simplified into springs representing stiffness of the substructure. In the same way, Ye [7,8] used an equivalent spring to simulate connections between the primary structure and modular substructure when conducting seismic performance analysis. There are other forms of TMDs derived from PTMDs.…”