Sierra, Armando

Fast Nonlinear Response History Analysis

Abstract eng:
Nonlinear response history analysis (RHA) has been a powerful tool in performance-based seismic engineering for validating proposed design of new or performance assessment of existing structures. In this approach, the seismic demands are determined by nonlinear RHAs of the structure excited by several ground motion acceleration records. When it is applied to structural systems with a large number of degrees of freedom such as three-dimensional models of tall buildings, bridges, or dams, the analyses can be computationally challenging and time consuming. The prolonged computing times become even more prominent in parametric studies or in incremental dynamic analyses where a computer model of the structure is subjected to a series of nonlinear RHAs by systematically increasing the intensity of input excitation. In order to reduce the computation time, this study proposes a practical method whereby leading and trailing weak signals in the acceleration record are trimmed, and remaining record is downsampled. The proposed method preserves significant frequency characteristics of the original record including its S-phase. The parameter to identify leading and trailing portions of the record to be trimmed is the maximum roof displacement calculated by implementing the uncoupled modal response history analysis. This parameter is selected because it represents the characteristics of both the ground motion and structural response with the goal of obtaining a highly efficient RHA without significant error. Test results based on three-dimensional computer models of idealized 5, 10, 15 and 20-story reinforced concrete structures demonstrate that the proposed method is not only viable, but also capable of controlling discrepancies in estimates of engineering demand parameters (EDPs) such as peak roof displacement. Performance of the proposed method is evaluated in terms of a goodness of fit test, comparing peak roof displacements obtained from the trimmed and downsampled records under uni-directional excitations with those from the original records.

Contributors:

Reyes, Juan

Conference Title:

Proceedings of the 16th World Conference on Earthquake Engineering

Conference Title:

16th World Conference on Earthquake Engineering

Conference Venue:

Santiago (CL)

Conference Dates:

2017-01-09 / 2017-01-13

Rights:

Text je chráněný podle autorského zákona č. 121/2000 Sb.