Design and Experimental Analysis of Seismic Isolation Bearings for Nuclear Power Plant Containment Structures

The aim of this study was to further research the mechanical properties of epoxy thick-layer rubber isolation bearings, adopting orthogonal design and efficacy coefficient methods in order to optimize the geometric dimensions and material parameters of the bearing, summarizing the influence of various factors on the overall performance indicators of the bearing, and determining the optimal plan through parameter adjustment. Through a combination of experiments and simulations, the fundamental characteristics of epoxy thick-layer rubber isolation bearings are studied to determine the influence law of vertical pressure on their horizontal stiffness, vertical stiffness, and damping ratio. The analysis results suggest that epoxy plate thick-layer rubber isolation bearing exhibits stable deformation ability and possesses distinctive damping characteristics. Furthermore, it is observed that the horizontal stiffness of these bearings gradually diminishes as the vertical pressure increases. When the shear displacement reaches 80 mm, there is a notable strengthening effect observed in the horizontal stiffness of the bearing. This strengthening phenomenon proves advantageous in preventing damage to the bearing due to excessive displacement; furthermore, it is noteworthy that the vertical stiffness and damping ratio of the bearing increased with the rise in vertical pressure.