Open-Space Damping System Description, Theory, and Verification

Seismic energy dissipation systems are typically installed in buildings within diagonal or chevron bracing to improve the seismic performance by reducing drift, and under certain conditions by reducing acceleration. Alternative installation methods have been developed in which novel mechanisms are used to magnify the displacements within the damping system, and thus improve performance when drift is small, and to reduce the cost of the damping system. Examples are the lever-arm, the toggle-brace, the coupled-truss, and the scissor-jack damper systems, which have found a limited number of applications. All damping system installation methods visually and physically obstruct an otherwise accessible area within the bay of the frame to which they are installed. This drawback has resulted in the occasional rejection of use of damping systems by architects. This paper introduces a novel configuration for damping devices with the main advantage of preserving open space within the frame of installation (hence the name open space damping system). The paper introduces the concept, presents the theory, and then presents computational models to verify the theory and to investigate the effects of the frame configuration, frame deformations, large rotations of the damping system, and frame inelastic action on the effectiveness of the system. (C) 2016 American Society of Civil Engineers.