The earthquake resistance of buildings can increase by using of special ingredients which are working as hysteretic dampers. Within softly severe earthquakes these dampers are working as rigid members which reduce structural deformations, while during very severe earthquakes the dampers are working as energy absorbers which limit the quasi-resonant build-up of structural deformations and forces.
The hysteretic dampers are not necessary to bear the main structural loads, and therefore may be optimized for their needed stiffness and energy-absorbing traits. On the other hand, the main structural ingredients are not needed large energy-absorbing and they may therefore be optimized for their needed stiffnesses and load-bearing traits.
In many structures this segregation of ingredients functions leads to increased reliability at a lower primary cost. Under earthquake attack stractual loss should be reduced. Non- structural loss should have decreased within softly severe earthquakes, and for special types of structure it also should decreased for very severe earthquakes.
Different ways in which hysteretic dampers may be used in structures are discussed briefly.
The development of several kind of high-capacity, low-cost hysteretic damper, appropriate for use in structures, is described. The dampers use solid steel beams deformed plastically in different mixtures of torsional, sinuous and shear deformations.
The development of hysteretic dampers for the protection of structures against earthquake attack, carried out at the Physics and Engineering Laboratory over the past six years.