117 research outputs found
CHAOS DYNAMICAL ANALYSIS OF EEG DATA(Session I : Cross-Disciplinary Physics, The 1st Tohwa University International Meeting on Statistical Physics Theories, Experiments and Computer Simulations)
この論文は国立情報学研究所の電子図書館事業により電子化されました
Semi-actively implemented non-linear damping for building isolation under seismic loadings
It is well-known that semi-active solution can achieve building isolation with much less energy requirements than active solutions. Also, it has been shown in previous studies that compared to linear damping, non-linear damping performs better for building isolation under sinusoidal ground motions. The present study is concerned with the extension of the application of the semi-actively implemented non-linear damping to building isolation under seismic loadings. A two-degree-of-freedom (2-DOF) scaled building model is used for simulation studies. Experimental tests on a physical building model have been used to validate the effectiveness of the 2-DOF scaled building model in representing the behaviors of a physical building structure. The optimal design of the semi-actively implemented non-linear damping for building isolation under design seismic motions is then carried out using the 2-DOF scaled building model based on simulation studies. The results show that an optimal design of semi-actively implemented non-linear damping can improve the performance of building isolation under design seismic motions in terms of both absolute acceleration and inter-story drift
Nonlinear damping based semi-active building isolation system
Many buildings in Japan currently have a base-isolation system with a low stiffness that is designed to shift the natural frequency of the building below the frequencies of the ground motion due to earthquakes. However, the ground motion observed during the 2011 Tohoku earthquake contained strong long-period waves that lasted for a record length of 3 min. To provide a novel and better solution against the long-period waves while maintaining the performance of the standard isolation range, the exploitation of the characteristics of nonlinear damping is proposed in this paper. This is motivated by previous studies of the authors, which have demonstrated that nonlinear damping can achieve desired performance over both low and high frequency regions and the optimal nonlinear damping force can be realized by closed loop controlled semi-active dampers. Simulation results have shown strong vibration isolation performance on a building model with identified parameters and have indicated that nonlinear damping can achieve low acceleration transmissibilities round the structural natural frequency as well as the higher ground motion frequencies that have been frequently observed during most earthquakes in Japan. In addition, physical building model based laboratory experiments are also conducted, The results demonstrate the advantages of the proposed nonlinear damping technologies over both traditional linear damping and more advanced Linear-Quadratic Gaussian (LQG) feedback control which have been used in practice to address building isolation system design and implementation problems. In comparison with the tuned-mass damper and other active control methods, the proposed solution offers a more pragmatic, low-cost, robust and effective alternative that can be readily installed into the base-isolation system of most buildings
Mutations in the bacterial cell division protein FtsZ highlight the role of GTP binding and longitudinal subunit interactions in assembly and function
Shaking table experiment of fault-tolerant seismic vibration control of a building based on sensor reliability
The authors propose a compensation method using the Kalman filter and sensor
reliability parameters to assure the continuous performance of vibration control even if sensor failures
occur. The effectiveness of the proposed method was verified by conducting a shaking table test using
a three-story specimen with an active mass damper, which is a small-scale model of a 15-story building.
As a result of the shaking table test with simulated sensor damage, it was confirmed that the responses
of inter-story drift angle and absolute acceleration were reduced by the proposed compensation method
in comparison with a case without the proposed method.Non UBCUnreviewedThis collection contains the proceedings of ICASP12, the 12th International Conference on Applications of Statistics and Probability in Civil Engineering held in Vancouver, Canada on July 12-15, 2015. Abstracts were peer-reviewed and authors of accepted abstracts were invited to submit full papers. Also full papers were peer reviewed. The editor for this collection is Professor Terje Haukaas, Department of Civil Engineering, UBC Vancouver.Facult
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