Numerical study of self-centering concrete wall system under cyclic loading

Abstract Self-centering concrete wall system is becoming more and more popular in recent years due to its obvious advantages in reducing earthquake damage, small residual drift and being easy to repair. In this paper, three dimensional (3D) finite element (FE) models for a series of self-centering concrete walls are developed to predict the responses of such walls under lateral cyclic loading. The influences of five parameters including initial external pressure, equivalent pre-pressure, contribution ratio of axial load, aspect ratio of walls and prestressed tendons (PTs) location on the seismic performance of self-centering concrete walls are systematically investigated. Results show: (1) The initial stiffness , strength and energy dissipation capacity of the self-centering wall continue to increase with an increase of the axial load, but the pinching effect of the hysteresis curves is significantly weakened, which means the self-centering capacity is reduced, especially when the axial compression ratio increases to a certain degree and the self-centering capacity of the wall is basically lost; (2) The self-centering capacity and energy dissipation capacity are almost independent of the contribution ratio of two axial loads, when the total axial load remains unchanged; (3) Under the same conditions, the high wall has better self-centering capacity, and the low wall has better energy dissipation capacity, which is associated as different mechanical properties and failure modes under cyclic loading; (4) Increasing the distance S between the PT bar and the centerline of the wall is beneficial to improve the lateral stiffness , strength and energy dissipation capacity of wall panels, but causes a large residual drift and bad self-centering capacity simultaneously. In addition, the distribution of tendons when they remain unyielding has a negligible effect on self-centering behavior of the walls.