Influence of geometric functions of frictional pendulum isolator with variable curvature under near-field earthquake
Subject Areas : Analysis of Structure and EarthquakeKeywords: friction pendulum isolator, variable curvature, near-filed earthquakes,
Abstract :
Frictional pendulum systems are one of the most widely used isolation systems. Frictional isolators are of the common type of the conventional isolators. Among this group, the frictional pendulum isolator has an important situation. Due to the advent of these systems in recent years, no significant research has been carried out regarding the design and analysis of this type of isolator. Therefore, in this study, an attempt has been made to fully study the behavior of frictional pendulum seismic isolators by examining this separator with variable curvature under near-field earthquake. In order to evaluate the seismic behavior of frictional pendulum separators with variable curvature, firstly, different geometric functions were selected for the non-spherical slip surface and the relationships required for their dynamic analysis were obtained. Then, a numerical model was presented to analyze the time history of the structure isolated by these isolators and the behavior of frictional pendulum isolators with variable curvature was simulated using MATLAB software. The results of this simulation for the three isolators including fourth order function (O4), sixth order function (O6) and FPS indicated that the frictional pendulum isolators perform better than FPS isolators. When structures are exposed to earthquakes with low intensity level (far-filed), the most suitable function to improve the optimal performance of an isolated structure is fourth order function and when the structure is subjected to severe earthquakes (near-filed), the sixth order function will perform well.
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