Civil and Environmental Engineering Department Seminar: Enhanced Fiber-Based Frame Model for Simulating Cyclic Degradation of Reinforced Concrete Beam-columns
Seminar | February 9 | 10-11 a.m. | 542 Davis Hall
Robust nonlinear structural analysis is fundamental to estimate seismic demands on structures and accurately assess their seismic performance. Structural simulations employing frame-element models face numerical challenges that preclude rigorous prediction of softening or response degradation of structural members; the simulated inelastic damage within the member can localize in an unphysical way that depends on the finite element discretization. To combat this problem in a generic and rigorous manner, a nonlocal formulation is adopted to enhance fiber-based frame models used to simulate reinforced concrete (RC) beam-columns. Using this approach, concrete damage in compression is treated as a distributed quantity that is informed by a physical characteristic length of the material, and is independent of the member discretization. The nonlocal model is applied to simulations of the post-peak response of RC columns under cyclic loading, and validated against available experimental data. The nonlocal approach is shown to alleviate spurious localization of damage, and enable robust simulation of the degrading cyclic response of RC columns. The proposed methodology can be applied in parametric simulations to generate accurate seismic collapse fragilities for RC buildings.