Dual Ductility Mode Shear Walls: Concept and Behavior

Shear walls are among the most common lateral load resisting systems, which are not recognized as efficient ductile structural components. Using any opening in the wall leads to disperse the inelastic behavior across the height of the wall and employ both flexural and shear ductility capacity of the system at the base and around the openings, respectively. Simple models were utilized to study the role of large openings in inelastic dynamic behavior of shear walls. Despite the constant total input energy, the amount of dissipated energy at the lower part of these walls is decreased to about two-third the value of ordinary shear walls. Consequently, the ductility demand diminished in the plastic hinge at the base and the required reinforcement detailing becomes simpler. However, marginal gains observed in the structural response such as base shear, base moment, inter-story drift and story displacement. Furthermore, to obtain the crack patterns and the ductility of the walls, static inelastic analyses were carried out using accurate finite element models. The results reveal that despite a small reduction in the strength of shear walls with openings, the crack patterns distribute more uniformly, and the ductility increases as the opening becomes larger.