Damage in a reinforced concrete member is a process due to loading. In case of load increase,
this process accelerates and leads to member destruction. Damage assessment in the reinforced
concrete members such as shear walls is of great importance. Damage index represents the
structural damage. Besides, the structural damage or complete demolition in a member is a result of
different factors such as concrete fracture, damage of reinforcing bars or continuity between
concrete and reinforcing bars. A simplifying assumption in the modeling and non-linear analysis of
shear walls is to assume that longitudinal bars will not buckle between two transversal
reinforcements or ties. As a matter of fact, when the longitudinal bar under compression inclines to
buckle and in the other hand this behavior is not considered in numerical modeling, this assumption
will lead to a considerable difference between the analytical and experimental results. In this
research, by means of calculating the damage index and considering buckling effect of longitudinal
reinforcement related to transversal reinforcements, the non-linear behavior of shear walls assessed.
The buckling effect of longitudinal reinforcements applied in stress-strain curve and the model of
Park-Ang is used to estimate damage index in reinforced shear walls. The numerical results show
that considering the buckling effect leads to a considerable difference in the damage index and the
structure reaches its destruction limit sooner but more effect of buckling for large damage indices
(DPA>=2) can be seen.