Sensitivity of building response to nonlinear analysis models

Nonlinear time history analysis is being increasingly utilized in the seismic design and evaluation of building structures. The general intent of such an analysis is to better understand the behavior of a building subjected to a given seismic motion. However, the methodology and particularly the modeling of the structural element properties have a significant impact on the results of this type of analysis. This paper evaluates the analytical models and the incorporated assumptions in two commonly used nonlinear programs: DRAIN-2DX 1·10 and IDARC 4·0. An instrumented reinforced concrete frame building is analyzed using both programs, and the analytical results are compared with the recorded data. A parametric study follows the program comparison to develop an understanding of the impact of various parameters involved in such an analysis. The study indicates that varying degrees of accuracy are possible with nonlinear time history analysis, depending on the program used and the assumptions incorporated. This paper also evaluates the sensitivity of the analytical results to the parameters involved. Copyright © 1999 John Wiley & Sons, Ltd.