Book excerpt: The purpose of this monograph is to impart basic concepts of the supplemental energy dissipation technology to design engineers, architects, and building officials so they can understand its benefits and limitations in structural applications. The approach is introductory. References are cited throughout the monograph for readers who wish to study the subject in more depth.Supplemental energy dissipation systems are recent innovations to improve earthquake building performance. Research has led to a better understanding of the effects of supplemental energy dissipation on the earthquake response of buildings. Over the last 20 years, significant progress has been made in developing manufactured systems. They are being reliably designed and installed in new as well as existing buildings.Development of design codes and standards for energy dissipation systems has progressed slowly. This monograph summarizes information on their use in designing new earthquake-resistant buildings and upgrading the seismic performance of existing buildings. The following areas are covered:? The physical consequences of adding energy dissipation systems to a structure for various types of input motion? Summary of generic energy dissipation device characteristics? Summary of pros and cons of specific device characteristics in meeting selected design objectives? Seismic design limits for selecting energy dissipation systems? Design approaches for the limits of elastic or inelastic response