Simple Nonlinear Flexural Stiffness Model for Concrete Structural Walls

Abstract

A trilinear bending moment–curvature model is proposed for the nonlinear static (pushover) analysis of concrete walls. To account for the effect of cracking on the flexural stiffness of concrete walls in a simple yet accurate way, the elastic portion of the bending moment–curvature relationship is modeled as bilinear. To account for the influence of cyclic loading on tension stiffening of cracked concrete, the concept of upper-bound response for a previously uncracked wall, and lower-bound response for a severely cracked wall is introduced. To validate the proposed model, the results of a large-scale test on a slender concrete wall are compared with predictions from the model. The application of the proposed model in a pushover analysis of a 131-m-(430-ft) high coupled-wall structure demonstrates the importance of accurately modeling the nonlinear flexural stiffness of concrete walls.