Simplified optimal design of MDOF structures with negative stiffness amplifying dampers based on effective damping

Wang, Meng; Sun, Fei‐Fei; Nagarajaiah, Satish

doi:10.1002/tal.1664

Cited by 51 publications

(36 citation statements)

References 56 publications

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“…Due to this complexity of the retrofitting problem, where NSDs and FVDs are added simultaneously, a few studies focused on this problem and even adopted optimization methods. 44,45 Shu et al 44 considered an inelastic single degree of freedom structure equipped by NSD and dampers; dimensional analysis was adopted while the Monte Carlo method was utilized to discover the optimal range of the design parameters. Wang et al 45 investigated linear multi-degree of freedom systems with linear NSDs and supplemental dumping, where the NSDs and dampers properties were optimized using a simplified method.…”

Section: Introductionmentioning

confidence: 99%

Performance‐based seismic retrofitting of frame structures using negative stiffness devices and fluid viscous dampers via optimization

Idels

Lavan

2021

Earthq Engng Struct Dyn

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In this paper, an optimization approach for the seismic retrofitting of inelastic moment resisting frames (MRFs) equipped with nonlinear fluid viscous dampers (FVDs) and negative stiffness devices (NSDs) is presented. The goal of the optimization is to minimize a cost-related objective function, which accounts for the cost of the supplemental FVDs and NSDs. The mechanical properties and the topological layout of both the FVDs and NSDs are considered as design variables and simultaneously optimized during the optimization process. A loss estimation analysis is utilized as a performance constraint, where the PEER framework is adopted. The structural response is evaluated using a nonlinear time history analysis (NTHA), which accounts for the nonlinear behavior of the MRF elements, FVDs, and NSDs. The optimization problem is formulated using differentiable functions only, making it suitable for an efficient gradient-based optimization solution scheme. The gradients are efficiently derived using the adjoint sensitivity analysis approach. Two numerical examples show the robustness and efficiency of the presented methodology, where the optimized design relies on NSDs and FVDs in both examples.

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Section: Introductionmentioning

confidence: 99%

Performance‐based seismic retrofitting of frame structures using negative stiffness devices and fluid viscous dampers via optimization

Idels

Lavan

2021

Earthq Engng Struct Dyn

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“…Quazi Zero Stiffness (QZS) or negative stiffness (NS) oscillators aim to significantly increase the natural period the system, as in the case of the conventional base isolation approaches. QZS and NS oscillators find numerous applications in seismic isolation [14][15][16][17][18][19][20][21]. The accelerations and inter-story drifts are simultaneously reduced by weakening the structure (reducing strength) and introducing additional damping.…”

Section: Introductionmentioning

confidence: 99%

Feasibility Assessment of Stiff Seismic Base Absorbers

Kapasakalis

Antoniadis

Sapountzakis

2021

J. Vib. Eng. Technol.

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A radically new concept of a Stiff Seismic Base Absorber (SBA) is proposed. An inerter is first implemented, connecting directly the structure to the ground. This results to the decrease of the natural frequency of the structure, without the decrease of the structural stiffness. Parallel, an extension of the KDamper is used, in order to increase the apparent damping behavior of the inerter. A negative stiffness (NS) element connects the additional mass of the SBA to the structure and a positive stiffness element the additional mass to the base. Also, an artificial damper is placed in parallel with each stiffness element. The design of the SBA is based on an appropriate optimization approach, which includes the following novel features: i) the SBA foresees variation in all stiffness elements, ii) the optimal system parameters are selected based on engineering criteria with proper constraints and limitations to the system dynamic responses, iii) the earthquake input motion is selected according to the seismic design codes, iv) a displacementdependent non-linear configuration is proposed for the realization of the NS element, and v) the detuning phenomena are observed via sensitivity analysis. Compared to other vibration absorbers, the SBA presents a number of advantages. An improved superstructure dynamic behavior is observed combined with small base displacements, in the order of a few centimeters. The drastically reduced base displacements render the implementation of the SBA feasible using conventional structural elements. As a result, the SBA is a possible retrofitting option for seismic protection.

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“…Jadhav and Shaikh (2019) presented an optimization study involving NSDs based on seismic response control. Another kind of passive NSD, called negative stiffness amplifying damper (NSAD) (Wang et al, 2019b;2019a), utilizes a combination of TNS and Maxwell damping element (MDE). It has been shown that NSAD achieves increased damping (called damping magnification) and is effective in seismic control under both FF-and NF-type excitations.…”

Section: Introductionmentioning

confidence: 99%

Seismic Performance of the Inerter and Negative Stiffness–Based Dampers for Vibration Control of Structures

Islam

Jangid

2021

Front. Built Environ.

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Passive energy dissipation devices or supplemental damping devices have been successfully implemented into structures for controlling the excessive vibrations under wind and seismic excitation. Recent developments in the form of negative stiffness dampers (NSDs) and inerter-based vibration absorbers (IVAs) as potential energy dissipation devices are of considerable interest to researchers. The present study evaluates the performance of the combined NSD and IVA as a possible alternative to the traditional energy dissipation devices such as viscous dampers (VDs) and viscoelastic dampers (VEDs). The mathematical formulation and optimal design of the combined NSD and IVA mechanism are presented. A 20-storey benchmark building is modeled as a multi-degree-of-freedom (MDOF) shear building. The dynamic equations for the MDOF building are written in the state-space form, and a simple optimization approach based on effective modal damping is prescribed. Comparative performance between traditionally applied and novel IVA and NSD is investigated. The design considerations to analyze structures employing combined NSDs and IVAs are developed. It is demonstrated that NSDs and IVA-based passive energy dissipation devices are the most efficient devices in reducing inter-storey drifts and floor accelerations compared with VDs and VEDs using the same damping coefficient.

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Simplified optimal design of MDOF structures with negative stiffness amplifying dampers based on effective damping

Cited by 51 publications

References 56 publications

Performance‐based seismic retrofitting of frame structures using negative stiffness devices and fluid viscous dampers via optimization

Performance‐based seismic retrofitting of frame structures using negative stiffness devices and fluid viscous dampers via optimization

Feasibility Assessment of Stiff Seismic Base Absorbers

Seismic Performance of the Inerter and Negative Stiffness–Based Dampers for Vibration Control of Structures

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