Abstract
In this paper, we investigate vertical mechanical characteristics of Base-isolated Rubber Bearings from tensile to high-compressed stress condition (-20〜300kg/cm^2), approaching theoretical and experimental studies. Then we propose the theoretical expression of the vertical stiffness covering both tensile and compressed condition with adopting a concept of equivalent Poason's ratio (υe ). And we carried out experiments using reduced and actual Rubber Bearings those diameters were 7, 16, 25, 50 and 80 cm respectively. Experimental results show that we can express the vertical stiffness by the proposing expression, adopting (for example)υe = 0.25 under compressed condition or υe = 0.02 under tensile condition as concerning actual Rubber Bearing, which first shape factor (S1) is about 32. And further, we get the result that the Bearing's compressed buckling stress is dependent upon the size of S1, and the Bearing's buckling stress can reach 600kg/cm^2 when that is about 32.
