Title:
SP-339-11: Recommendations for Modeling the Nonlinear Response of Flexural Reinforced Concrete Walls Using Perform
Author(s):
Laura N. Lowes, Dawn E. Lehman, and Carson Baker
Publication:
Symposium Paper
Volume:
339
Issue:
Appears on pages(s):
173-195
Keywords:
structural walls, finite element modeling, seismic response, flexure
DOI:
10.14359/51724702
Date:
3/1/2020
Abstract:
The PERFORM-3D software package is used commonly in engineering practice to conduct nonlinear dynamic analyses of reinforced concrete walled buildings to their seismic response. However, few studies have evaluated or improved on common modeling approaches for structural concrete walls. The research presented here was conducted to establish best practices for modeling the full nonlinear response of walls exhibiting common flexural failure modes. First, an experimental data set consisting of eight planar concrete walls was collected; these walls were spanned a range of length-to-thickness ratios, shear stress demands, axial load ratios, and longitudinal reinforcement configurations. For each wall specimen, a reference numerical model was created using typical modeling methods as proposed by Powell. Comparison of simulated and measured cyclic response histories show that typical modeling techniques result in relatively inaccurate simulation of cyclic response and very inaccurate simulation of drift capacity. To improve the model accuracy, experimental data were used to determine appropriate values for the steel and concrete material model cyclic response parameters. Experimental data and mathematical definitions for the concrete compressive energy were used to develop recommendations for defining concrete post-peak stress-strain response to achieve accurate, mesh-independent simulation of drift capacity. Finally, recommendations for the minimum number of elements were examined. Comparison of simulated and measured cyclic response histories show that the new modeling recommendation result in accurate, mesh independent simulation of cyclic response, including drift capacity. Future work will evaluate the proposed modeling approach for asymmetric and flanged walls.