EFFECT OF ROTATIONAL SPRING OF ELASTIC CANTILEIVER COLUMN ON MECHANISM OF DAMAGE CONTROL FOR TWO STORY BRACED FRAME WITH RESTRAINT BRACES

Abstract

In our previous paper, it is shown that story drift concentration is restraint by columns of two braced frames with pinned and fixed column bases. But embedded column bases are nearly fixed and exposed column bases are nearly pinned in the real structures. These column bases is designed as rotational springs. In this paper, the equations of the drift concentration factor for two story braced frames with columns base of rotational springs have been developed from the equilibrium conditions of the frames subjected to lateral force. This paper clarifies the relationship between drift concentration and ratio of column flexural stiffness and column rotational stiffness.