Results Of Nonlinear Response History Analyses Research Articles

A simplified analysis procedure for performance-based earthquake engineering of buildings

Accurate assessment of the seismic performance of buildings and the computation of direct and indirect economic losses resulting from earthquake shaking requires the use of analysis procedures that reliably predict distributions of peak structural response quantities, including story drift, floor velocity, and floor acceleration. A linear analysis procedure was developed for this purpose and is suitable for application to low- and medium-rise buildings of regular configuration. The analysis procedure was calibrated using results of nonlinear response-history analysis of 3-, 5-, 9-, and 15-story models of three dimensional archetype buildings constructed with moment frames, braced frames and shear walls.

Assessment of ground motion selection criteria specified in current seismic provisions with an accurate selection algorithm

It is important to select proper ground motions for accurately estimating seismic demands using linear and nonlinear response history analyses (RHA). Current seismic design provisions such as ASCE 7–10 provide criteria for selecting ground motions. In this study, an accurate and computationally efficient algorithm for selecting and scaling ground motions is proposed, which satisfies the ASCE 7–10 criteria. The ASCE 7–10 ground motion selection criteria with the proposed algorithm is assessed using the results of nonlinear response history analyses of twelve single degree of freedom (SDF) systems and one multi-degree of freedom (MDF) system. In order to investigate the effect of the numbers of selected ground motions, period ranges for spectral matching, library sizes, and structural periods on selection results, parametric studies are conducted based on the results of nonlinear RHA. This study shows that the target seismic demands for all model SDF and MDF systems can be predicted using the mean seismic demands over seven and ten ground motions selected according to the proposed method within an error of 30 and 20%, respectively.

Accuracy of Advanced Methods for Nonlinear Static Analysis of Steel Moment-Resisting Frames

The reliability of advanced nonlinear static procedures to estimate deformation demands of steel momentresisting frames under seismic loads is investigated. The advantages of refined adaptive and multimodal pushover procedures over conventional methods based on invariant lateral load patterns are evaluated. In particular, their computational attractiveness and capability of providing satisfactory predictions of seismic demands in comparison with those obtained by conventional force-based methods are examined. The results obtained by the static advanced methods, used in the form of different variants of the original Capacity Spectrum Method and Modal Pushover Analysis, are compared with the results of nonlinear response history analysis. Both effectiveness and accuracy of these approximated methods are verified through an extensive comparative study involving both regular and irregular steel moment resisting frames subjected to different acceleration records.

Validation of the 2000 NEHRP Provisions’ Equivalent Lateral Force and Modal Analysis Procedures for Buildings with Damping Systems

Equivalent lateral force and modal analysis procedures for yielding buildings with damping systems were developed, validated, and incorporated in the 2000 NEHRP Provisions. Key to the implementation of the procedures was the validation process that demonstrated the accuracy of the proposed procedures. The procedures for implementing yielding, viscoelastic, linear viscous, and nonlinear viscous dampers were tested using the results of nonlinear response-history analysis on sample three- and six-story frames and were found to be robust.