Open Access

ARTICLE

Optimization of Nonlinear Vibration Characteristics for Seismic Isolation Rubber

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

1 Nihon University, College of Industrial Technology, Dept. of Mathematical Information Engineering, Japan.
2 Ex-Graduate Student, Nihon University, College of Industrial Technology, Dept. of Mathematical Information Engineering, Japan.
3 Mississippi State University, U.S.A.
4 Nihon University, College of Industrial Technology, Dept. of Mathematical Information Engineering, Japan.

Computer Modeling in Engineering & Sciences 2017, 113(1), 1-15. https://doi.org/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 seismic responses in the cases with and without the laminated rubber. In addition, the hysteresis restoring-force characteristic of the laminated rubber, which minimizes the seismic response of the building, was optimized by using a genetic algorithm (GA). Based on these results, the optimum restoring-force characteristic for different earthquakes was determined. As a result, it was clarified that the developed optimization method can determine the vibration characteristics of the laminated rubber for minimizing the damage to the structure in the design phase.

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