Dynamic response and optimal design of structures with large mass ratio TMD

Abstract

This paper investigates the dynamic behavior and the seismic effectiveness of a non-conventional Tuned Mass Damper (TMD) with large mass ratio. Compared with conventional TMD, the device mass is increased up to be comparable with the mass of the structure to be protected, aiming at a better control performance. In order to avoid the introduction of an excessive additional weight, masses already present on the structure are converted into tuned masses, retaining structural or architectural functions beyond the mere control function. A reduced order model is introduced for design purposes and the optimal design of a large mass ratio TMD for seismic applications is then formulated. The design method is specifically developed to implement High-Damping Rubber Bearings (HDRB) to connect the device mass to the main structure, taking advantage of combining stiffness and noticeable damping characteristics. Ground acceleration is modeled as a Gaussian random process with white noise power spectral density. A numerical searching technique is used to obtain the optimal design parameter, the frequency ratio alpha, which minimizes the root-mean-square displacement response of the main structure. The study finally comprises shaking table tests on a 1:5 scale model under a wide selection of accelerograms, both artificial and natural, to assess the seismic effectiveness of the proposed large mass ratio TMD. Copyright (C) 2011 John Wiley & Sons, Ltd

Earthquake Protection of Existing Structures with Limited Seismic Joint: Base Isolation with Supplemental Damping versus Rotational Inertia

“…limited to the few ones discussed in this paper. Among these strategies, we mention the coupling of adjacent buildings by means of passive damping devices to reduce the risk of pounding [50][51][52] and to improve the seismic performance of the two systems [53][54][55], the introduction of viscous dampers along the height of the building that produce desired levels of interstory drifts while reducing seismic forces [56,57], the interstory isolation by the use of seismic isolators at levels other than the base along the height of a building [58,59], and the interstory isolation implemented by converting masses already present on the structure into tuned masses according to a nonconventional TMD scheme [38,60]. Moreover, there are a range of supplemental dampers that do not have a viscous nature, for example, buckling restrained braces, yielding fuse systems, and the HF2V device based on the lead extrusion technology [61][62][63][64], to quote just a few.…”

Aseismic smart building isolation systems under multi-level earthquake excitations: Part I, conceptual design and nonlinear analysis

“…Recently, to overcome this reliability related problem and support the availability of the use of large TMDs, considerable studies have been devoted to the optimal design of TMD-like building isolation systems to enable proper selection of absorber parameters [11][12][13][14][15]. Especially, the authors of this study suggested the TMD principle-based design of the "TMD (passive and semiactive) building systems" and its seismic performances were evaluated over three probabilistically scaled suites of earthquake records parameters [16][17][18].…”

Roof Isolation with Tuned Mass-based Systems and Application to a Prefabricated Building

“…In the past, TMDs with small mass compared to the mass of the main system were used, while recently the idea of using a TMD with a high mass ratio was strongly advocated (De Angelis et al [8]), introducing the concept of non-conventional TMD. This system, having a mass ratio close to unity, offers a wider operating range compared to conventional ones, resulting in a better response of the structure in terms of absolute displacement as well as drift.…”