As mentioned above, comparative issue of energy dissipation and ratio of equivalent viscous damping in different states of wall crater has not been studied clearly.
Equivalent viscous damping is used to describe capacity of energy absorption in structures.
In this case, according to equation (1), values of equivalent viscous damping in each loading cycle are calculated.
In order to evaluate results better, two methods of fitting results of equivalent viscous damping, in terms of deformability coefficient for each wall system, was used and shown in figure (9).
The equivalent viscous damping coefficient [xi] is quantifying the hysteresis response of structural components, and as such, it is one of the key indicators describing their behavior.
Equivalent viscous damping [xi] calculated at hysteresis turning points is presented in Figure 10.
This results in slow increase of equivalent viscous damping coefficients Only after severe damages (after story drift d/h > 0.
Fast and nearly constant development of equivalent viscous damping coefficient _ was governed by high level of resistance of friction force to the imposed load in the cases of joint types CD2 and CD3.
The demand associated with the ground motion is represented by a combined elastic Acceleration and Displacement-Response Spectrum (ADRS) curve for various levels of equivalent viscous damping ratios.
In the capacity spectrum, the point at which both the curves interact with the same equivalent viscous damping ratio is the performance point which defines the demand imposed on the structure.
Friction damping is replaced by equivalent viscous damping
To carry out response spectrum analysis, effective stiffness (Keff) and the equivalent viscous damping
derived from the isolator's EDC (energy Dissipated per Cycle) are essential.