Improving the Performance of I-Shaped Dampers Using Stiffeners

Abstract

Research reports on the behavior of metallic dampers have confirmed that the I-shaped link, while designed under a shear mechanism, acts as a ductile fuse. The main weakness of these links is the reduction of stiffness of the system when they are connected directly to the diagonal member of the concentrically braced frame. To increase the stiffness and ultimate strength of the I-shaped links, increasing the thickness of the web plate has been proposed by researchers, which causes an increase in the imposed load on the members of the braces. An innovative idea to overcome this problem is adding diagonal stiffeners to the dampers. In this paper, the stiffening of the I-shaped links is examined numerically and parametrically using the finite element method (FEM). Numerical results reveal that the stiffeners not only prevent the buckling of the web plate (which causes improvement in its performance), but they also share the imposed loading. By adding the stiffeners, a thinner web plate can be used instead of increasing the thickness of the web plate to achieve larger ultimate strength and stiffness. The parametrical study indicated that the thickness of the stiffeners is much more important than the properties of the flange and web plate in case of the damper performance.