Evaluation of Simplified and State-of-the-Art Analysis Procedures for Steel Frame Buildings Equipped with Supplemental Damping Devices Based on E-Defense Full-Scale Shake Table Tests

Abstract

This paper summarizes a number of key findings that affect the use of linear and nonlinear analysis procedures for the seismic evaluation of steel frame buildings with supplemental damping devices and in particular, buckling-restrained braces (BRBs) and nonlinear viscous dampers (NVDs). The assessment is based on a comparison of various engineering demand parameters (EDPs) with experimental data obtained from a series of full-scale shaking table tests of a five-story steel building equipped with BRBs and NVDs. It is shown that: (1) there is no clear advantage between three-dimensional (3D) and two-dimensional (2D) analyses in the prediction of the dynamic behavior of regular plan view steel frame buildings regardless of the damper type; (2) incorporating the brace and nonlinear viscous damper axial flexibility in the analytical model of the test structure with NVDs significantly improves the overall numerical predictions; and (3) the current effective damping ratio recommended by ASCE 41-13 as part of linear static procedures for the evaluation of frame buildings with BRBs or NVDs may not be conservative enough. A new performance-based design tool called performance-spectra (P-Spectra) is able to reliably predict the EDPs of interest. The P-Spectra tool is also able to validate the efficiency of various damper solutions on the dynamic performance of the test structure. It is demonstrated that P-Spectra can be employed to predict estimates of potential residual deformations that traditional linear and nonlinear static procedures cannot.