Ayumi Takahashi^1,*, Kenya Kashiwagi², Tomoyuki Tsuchiya², Kazuhito Misaji¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.24, No.1, pp. 1-1, 2022, DOI:10.32604/icces.2022.08705

Abstract As a characteristic of seismic isolated laminated rubber, the rubber is torsional deformed when it was loaded in horizontal bi-direction, and breaks with less force than when loaded in unidirectional. It is necessary to extend the model which has been used for unidirectional analysis to the model which can be analyzed in bi-direction. As a previous study, Igarashi applied the Multiple Shear Springs (MSS) model which is a horizontal bi-directional model, and compared them with measured values to verify their validity [1]. The authors extended PFT-ELS method to MSS model which can analyze bidirection [2]. The ELS method is a… More >

Ayumi Takahashi^1,*, Tomoyuki Tsuchiya², Keiichi Motoyama³, Kazuhito Misaji¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.23, No.1, pp. 15-15, 2021, DOI:10.32604/icces.2021.08354

Abstract The seismic-isolation laminated rubber is used as a means of suppressing damage to the structures caused by an earthquake. To design the seismically isolated structure, it is important to calculate the dynamic response reflecting the rubbers characteristics accurately. The authors have applied the nonlinear vibration analysis method using the restoring force model of the power function type to the seismic response analysis of seismic isolation rubber in horizontal unidirectional [1-3]. However, when seismic isolation laminated rubber is loaded in horizontal bi-direction, the seismic isolation laminated rubber is torsional deformed and breaks with less force than when loaded in unidirectional. It… More >

Yafei Zhang^1,2, Ping Tan^1,2,*, Haitao Ma^1,2, Marco Donà^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.124, No.2, pp. 415-431, 2020, DOI:10.32604/cmes.2020.09054

Abstract A staircase provides the main escape way from a building in an emergency. Unfortunately, it may suffer severe damages or even collapse during an earthquake. For improving the seismic performance of staircases, this paper proposes an innovative staircase isolator with the features of lightweight, costeffective and ease of construction and replacement, which is formed by suitable engineering plastic shims between rubber layers. A connection construction scheme is also proposed for the isolated staircase. Systematic performance tests have been carried out to characterize the isolator in terms of mechanic behavior and ultimate states. The test results show that mechanical properties of… More >

A. Takahashi¹, K. Motoyama², K. Misaji^1,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.2, pp. 42-42, 2019, DOI:10.32604/icces.2019.05446

Abstract Seismic isolation laminated rubber is used as an effective means for suppressing damage to buildings and people in buildings by earthquakes. The restoring-force characteristic of the rubber has non-linerar-vibration characteristics which depend on the displacement amplitude. PFT-ELS (Equivalent linear system using the restoring force model of power function type) has been applied for calculating approximate responses of various non-linear-vibration systems [Kazuhito, M., et al. (1994); Koichi, S., et al. (1995); Koichi, S., et al. (1996)]. The authors have also applied to optimize the non-linear vibration characteristics of the isolation rubber using PFT-ELS and GA [Ayumi, T., et al. (2017)]. However,… More >

Tongfa Deng^1,2, Junping Zhang^1,3,*, Mahmoud Bayat⁴

Structural Durability & Health Monitoring, Vol.12, No.3, pp. 189-212, 2018, DOI: 10.3970/sdhm.2018.04392

Abstract The isolated curved girder bridge's vibration characteristics play a major part in the seismic responses of structures and anti-seismic properties. A clear analytic relationship between design parameters and the system's vibration characteristics could be established by its simplified dynamic analysis model, making it convenient for providing a reference to the optimization of design and safety analysis. A double-mass six-degree-of-freedom model for curved girder bridges with isolation bearings installed at the top of the bridge piers is built and a simplified analysis method for the vibration characteristics of the system is provided. Combined with the Matlab programming, the influences of radius… More >

Alireza Sarebanha^1,*, Andreas H. Schellenberg², Matthew J. Schoettler³, Gilberto Mosqueda⁴, Stephen A. Mahin^†

CMES-Computer Modeling in Engineering & Sciences, Vol.120, No.3, pp. 693-717, 2019, DOI:10.32604/cmes.2019.04846

Abstract Hybrid simulation can be a cost effective approach for dynamic testing of structural components at full scale while capturing the system level response through interactions with a numerical model. The dynamic response of a seismically isolated structure depends on the combined characteristics of the ground motion, bearings, and superstructure. Therefore, dynamic full-scale system level tests of isolated structures under realistic dynamic loading conditions are desirable towards a holistic validation of this earthquake protection strategy. Moreover, bearing properties and their ultimate behavior have been shown to be highly dependent on rate-of-loading and scale size effects, especially under extreme loading conditions. Few… More >

A. Takahashi¹, T. Shibata², K. Motoyama³, K. Misaji⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.113, No.1, pp. 1-15, 2017, DOI:10.3970/cmes.2017.113.001

Abstract A method for reducing the damage to a structure caused by an earthquake namely, using laminated rubber for seismic isolation is proposed, and the vibration characteristics of the rubber (which minimizes the seismic response of the structure during an earthquake) is optimized. A method called “Equivalent Linear System using Restoring Force Model of Power Function Type” (PFT-ELS) is applied to nonlinear vibration analysis of the rubber. In that analysis, a building with 15 layers of the laminated rubber is modeled. The seismic response of the building is analyzed, and the usefulness of the laminated rubber is demonstrated by comparing the… More >