scholarly journals Optimal Design and Distribution of Viscous Dampers for Shear Building Structures Under Seismic Excitations

2019 ◽  
Vol 5 ◽  
Author(s):  
Huseyin Cetin ◽  
Ersin Aydin ◽  
Baki Ozturk
Keyword(s):  
Optimal Design ◽  
Building Structures ◽  
Seismic Excitations ◽  
Viscous Dampers ◽  
Shear Building

scholarly journals Simultaneous Optimization of Elastic-Plastic Building Structures and Viscous Dampers Under Critical Double Impulse

2020 ◽  
Vol 6 ◽  
Author(s):  
Hiroki Akehashi ◽  
Izuru Takewaki
Keyword(s):  
Optimal Design ◽  
Damping Coefficient ◽  
High Yield ◽  
Total System ◽  
Building Structures ◽  
Viscous Dampers ◽  
Design Algorithm ◽  
Main Building ◽  
Elastic Plastic ◽  
Strength Design

A new method for simultaneous optimal design of main building structures and viscous dampers is proposed for elastic-plastic multi-degree-of-freedom (MDOF) building structures subjected to the critical double impulse which is regarded as a representative of the main part of near-fault ground motions. The critical double impulse is characterized by the maximum energy input to the total system by the second impulse and the sum of the restoring force and the damping force in the first story attains zero by this critical input. The objective function is the maximum interstory drift along the building height. The original optimization problem is transformed into a problem of removing the most inactive story stiffness and damper damping coefficient. An efficient sensitivity-based design algorithm is developed for this simultaneous optimal design problem of main building structures and viscous dampers. It is pointed out that the order of changes of structural stiffness and damper damping magnitude is critical to the achievement of reasonable designs and cycle-by-cycle alternating redesign of story stiffness and damper damping coefficient is effective for its achievement. The double impulse pushover (DIP) analysis proposed in the previous paper (Akehashi and Takewaki, 2019) for determining the input velocity level of the critical double impulse is also conducted to disclose the response characteristics of the designed building structures and dampers. It is shown that the proposed design method enables the high yield-strength design with effective seismic energy absorption and the high limit-strength design effective for extremely large disturbances. The distributions of the maximum acceleration responses in an initial design and the final design are also presented for the one-cycle sine wave corresponding to the critical double impulse.

Influence of viscous dampers ultimate capacity on the seismic reliability of building structures

2021 ◽  
Vol 91 ◽  
pp. 102096
Author(s):  
Fabrizio Scozzese ◽  
Laura Gioiella ◽  
Andrea Dall'Asta ◽  
Laura Ragni ◽  
Enrico Tubaldi
Keyword(s):  
Building Structures ◽  
Ultimate Capacity ◽  
Viscous Dampers ◽  
Seismic Reliability

scholarly journals Time-Varying Wind Load Identification Based on Minimum-Variance Unbiased Estimation

2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Huili Xue ◽  
Kun Lin ◽  
Yin Luo ◽  
Hongjun Liu
Keyword(s):  
Damping Ratio ◽  
Estimation Method ◽  
Minimum Variance ◽  
Wind Load ◽  
Ar Model ◽  
Unbiased Estimation ◽  
Recursive Identification ◽  
Time Varying ◽  
Building Structures ◽  
Shear Building

A minimum-variance unbiased estimation method is developed to identify the time-varying wind load from measured responses. The formula derivation of recursive identification equations is obtained in state space. The new approach can simultaneously estimate the entire wind load and the unknown structural responses only with limited measurement of structural acceleration response. The fluctuating wind speed process is investigated by the autoregressive (AR) model method in time series analysis. The accuracy and feasibility of the inverse approach are numerically investigated by identifying the wind load on a twenty-story shear building structure. The influences of the number and location of accelerometers are examined and discussed. In order to study the stability of the proposed method, the effects of the errors in crucial factors such as natural frequency and damping ratio are discussed through detailed parametric analysis. It can be found from the identification results that the proposed method can identify the wind load from limited measurement of acceleration responses with good accuracy and stability, indicating that it is an effective approach for estimating wind load on building structures.

scholarly journals Damage Detection on Sudden Stiffness Reduction Based on Discrete Wavelet Transform

2014 ◽  
Vol 2014 ◽  
pp. 1-16 ◽  
Author(s):  
Bo Chen ◽  
Zhi-wei Chen ◽  
Gan-jun Wang ◽  
Wei-ping Xie
Keyword(s):  
Wavelet Transform ◽  
Damage Detection ◽  
Discrete Wavelet Transform ◽  
Sudden Change ◽  
Damage Index ◽  
Time Instant ◽  
Discrete Wavelet ◽  
Building Structures ◽  
Stiffness Reduction ◽  
Shear Building

The sudden stiffness reduction in a structure may cause the signal discontinuity in the acceleration responses close to the damage location at the damage time instant. To this end, the damage detection on sudden stiffness reduction of building structures has been actively investigated in this study. The signal discontinuity of the structural acceleration responses of an example building is extracted based on the discrete wavelet transform. It is proved that the variation of the first level detail coefficients of the wavelet transform at damage instant is linearly proportional to the magnitude of the stiffness reduction. A new damage index is proposed and implemented to detect the damage time instant, location, and severity of a structure due to a sudden change of structural stiffness. Numerical simulation using a five-story shear building under different types of excitation is carried out to assess the effectiveness and reliability of the proposed damage index for the building at different damage levels. The sensitivity of the damage index to the intensity and frequency range of measurement noise is also investigated. The made observations demonstrate that the proposed damage index can accurately identify the sudden damage events if the noise intensity is limited.

Optimal Design of Nonlinear Viscous Dampers for Protection of Isolated Bridges

2012 ◽  
pp. 370-398
Author(s):  
Alexandros A. Taflanidis ◽  
Ioannis G. Gidaris
Keyword(s):  
Optimal Design ◽  
Dynamic Behavior ◽  
Stochastic Simulation ◽  
Seismic Risk ◽  
Probabilistic Framework ◽  
Viscous Dampers ◽  
Nonlinear Characteristics ◽  
Bridge Model ◽  
Supplemental Dampers ◽  
Isolated Bridges

A probabilistic framework based on stochastic simulation is presented in this chapter for optimal design of supplemental dampers for multi - span bridge systems supported on abutments and intermediate piers through isolation bearings. The bridge model explicitly addresses nonlinear characteristics of the isolators and the dampers, the dynamic behavior of the abutments, and the effect of pounding between the neighboring spans to each other as well as to the abutments. A probabilistic framework is used to address the various sources of structural and excitation uncertainties and characterize the seismic risk for the bridge. Stochastic simulation is utilized for evaluating this seismic risk and performing the associated optimization when selecting the most favorable damper characteristics. An illustrative example is presented that considers the design of nonlinear viscous dampers for protection of a two-span bridge.

scholarly journals Experimental evaluation of a vibro-impact model for two adjacent shear-building structures

2018 ◽  
Vol 211 ◽  
pp. 03004
Author(s):  
Marcus Varanis ◽  
Arthur Mereles ◽  
Anderson Silva ◽  
José Balthazar ◽  
Ângelo Tusset ◽  
...  
Keyword(s):  
Beam Theory ◽  
Rotor Blades ◽  
Contact Theory ◽  
Building Structures ◽  
Impact Model ◽  
Nonlinear Characteristics ◽  
Strongly Nonlinear ◽  
Shear Building ◽  
The Impact ◽  
Euler Bernoulli Beam

The vibro-impact phenomenon is found in many engineering applications, from impact of floating ice with ships to rubbing between the stator structure and rotor blades in turbomachinery, and in most cases it is important to know the implication of this phenomenon in the mechanical system. This is often done by proposing vibro-impact models for describing the behavior of the system when subjected to periodically impacts. However, this modelling may be challenging due to the strongly nonlinear characteristics of the impact phenomenon. Therefore, this paper presents a vibro-impact model of two shearbuilding structures positioned side by side, where one of them is driven by an unbalanced DC motor. The structures were modeled using the Euler-Bernoulli beam theory and the contact was modeled based on the Hertz contact theory. In order to validate the model their responses were compared with experimental signals.

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