Structural optimal hybrid control strategies employing dynamic dual units: inerter and spring

This study investigates a novel electromagnetic tuned mass damper with flywheels (EM‐FW‐TMD) system for reducing building structure vibration. The EM‐FW‐TMD system comprises a tuned mass damper (TMD) system with an electromagnetic (EM) damper and flywheels (FW). The EM damping coefficient and inertance of the EM‐FW‐TMD are adjustable. A prototype EM‐FW‐TMD device is fabricated and tested to validate its adjustability. Sliding‐ and pendulum‐type EM‐FW‐TMD systems with various inerter configurations are investigated. The equations of motion for single‐ and multiple‐degree‐of‐freedom structures in which the two EM‐FW‐TMD systems are installed are derived. A parameter optimization method that considers inertance is proposed for the EM‐FW‐TMD systems. The control performance of the two EM‐FW‐TMD systems is extensively compared. Furthermore, for frequency detuning, a parameter redesign method is proposed for adjusting the inertance and EM damping coefficient of both types of EM‐FW‐TMD systems; the results indicate that the detuning effect can be significantly mitigated by this retuning method.

Section: Noveltymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Application of electromagnetic tuned mass damper with flywheels for controlling building structure vibration

Lin

2023

“…33,34 The authors mainly focus on the research of clutching inertia devices in seismic structural systems. 28,[35][36][37] Compared with the traditional inerter, the advantages of the clutching inertia dampers are: (1) In terms of construction, the clutch mechanism has mechanical advantages and can avoid considerable destructive impacts on both the structure and the transmission system of the device caused by the switching of structural motion states when suffering a large inertia (resulting from deceleration inertia). 9 This is crucial for the reliable and stable operation of the device under highfrequency excitations.…”

Section: Introductionmentioning

confidence: 99%

“…They have been investigated in various seismic structural systems, 9,11,28 base isolation systems, 29,30 TMD systems, 31,32 and rocking systems 33,34 . The authors mainly focus on the research of clutching inertia devices in seismic structural systems 28,35–37 . Compared with the traditional inerter, the advantages of the clutching inertia dampers are: (1) In terms of construction, the clutch mechanism has mechanical advantages and can avoid considerable destructive impacts on both the structure and the transmission system of the device caused by the switching of structural motion states when suffering a large inertia (resulting from deceleration inertia) 9 .…”

Section: Introductionmentioning

confidence: 99%

Dynamic performance of structures with clutching inertia‐damping system: Theoretical study

Liang,

Bai,

et al. 2023

Self Cite

This paper addresses performance limitations in passive clutching inertia devices due to the absence of flywheel deceleration damping. A solution introducing viscous damping to serve as the flywheel deceleration mechanism is proposed, thus forming the “CIDS” (Clutching Inertia‐Damping System). The study establishes a multi‐body motion analysis model for the CIDS within a single‐degree‐of‐freedom structure. Simulations investigate the impact of control force model parameters on the computation. The impact of additional damping on structural dynamic responses and the system's relative motion is thoroughly elucidated and revealed through dynamic simulations and multi‐body motion decomposition. The “ELS” (Equivalent Linear System) is introduced for the simplified performance assessment of CIDS. Expressions for equivalent damping and inertance are derived based on the equivalence of vibration period and energy in sinusoidal steady‐state vibration. The feasibility and accuracy of ELS for assessing CIDS's performance are validated through response analyses under harmonic and seismic excitations. Notably, displacement indicators exhibit higher precision than acceleration. When subjected to seismic excitation, selecting a more suitable excitation frequency to determine the corresponding equivalent damping can enhance the accuracy of ELS. Considering the frequency dependence of equivalent damping, a frequency‐domain‐based random response evaluation method is proposed. The influence of additional rotational damping, flywheel inertia, and structural natural period on random response is evaluated and analyzed. In CIDS with similar rotational damping and inertia, its control effect is related to the excitation. In summary, this study offers a structured framework for comprehending and evaluating the performance of CIDS, offering valuable insights into its potential engineering design, applications, and analysis.

“…Inerter-based shock absorption devices and models have attracted significant interest in structural vibration control. [1][2][3][4][5][6] In the early 1990s, some control devices with a structure similar to that of an inerter have been proposed and studied. 7,8 Until 2002, the concept of inerter was first proposed by Smith.…”

Section: Introductionmentioning

confidence: 99%

Theoretical and experimental analyses of structures with supplemental clutching inertia devices

Liang

2022

Self Cite

Clutching inertia device (CID) is a novel device that incorporates the function of an inerter and the clutching effect that can be provided by a ratchet. In this paper, the performance of an SDOF system with supplemental clutching inertia is investigated through theoretical analyses and experimental tests. First, the dynamic equation for a structure with a CID is built in the form of multi‐body motion. Second, an inertia device (ID), a CID, and an inertia‐enhanced CID (ECID) by reducers are designed for dynamic testing in a small‐scale steel structure. Third, the influence of clutching effect, flywheel inertia and accessory damping of the CID on the structural response is analyzed through a comparative study of numerical simulation and shaking table tests under harmonic and seismic excitation. The results confirm previous predictions that the clutching effect helps to reduce the resonant response of the structure and that the increase in flywheel inertia can further mitigate the resonant response when considering certain accessory damping in the CID. The increase in accessory damping, either viscous damping or friction damping, will obviously reduce the resonant response and resonant frequency of the controlled structure, and the structure with the ECID shows better performance than that of CID when considering the same accessory damping. It is confirmed that the tested CIDs improved the structural seismic performance by slightly prolonging the fundamental structural period and prominently controlling the response in resonant frequency and high frequency owing to the effect of supplemental clutching inertia and accessory damping.