Passive energy dissipation devices

In this chapter, the supplemental passive energy dissipation devices, metallic or hysteretic dampers, frictional, viscoelastic and viscous (linear and nonlinear) dampers, developed and studied over the years, are briefly described. For each type of device, the physical, mechanical and technological aspects are analysed by describing the construction, hysteretic behavior, physical models, advantages, and disadvantages. Then, the more appropriate mathematical laws to model their dynamic behavior, with particular reference to the viscous and viscoelastic, are described. Finally, a comparison between all the different types of device is reviewed and the main recommendations, reported in the international codes with specific reference to the viscous and viscoelastic, are explained.