Probabilistic Analysis of Steel Frame Subjected To Single and Repeated Earthquakes


Abstract eng:
A 3-story 4-bay steel moment resisting frame (MRF) is analyzed using the finite element analysis (FEA) software OpenSees. The frame is subjected to dynamic analysis, based on selected ground motions of past earthquakes, considering input uncertainties. Based on the fact that time history analysis is time consuming, probabilistic FEA may not be practical for dynamic analysis problems. Therefore, the probabilistic FEA is implemented using the multiplicative dimensional reduction method (M-DRM), which is automated in OpenSees using the Tcl programing language, in order to calculate the statistical moments of the response, e.g., mean and variance. This study shows that M-DRM can be considered as an efficient alternative method for the probabilistic analysis of these types of problems. In addition, this study examines how the same input uncertainties affect the structural response, e.g., inter-story drift, when the structure is subjected to different ground motions. First, the frame is subjected to single ground motion records under uncertainties in material properties. The results in terms of coefficient of variation (COV) indicate that the frame’s structural response is not primarily affected from the material variations. However, considering as a random variable the applied mass in each node, the results indicate that the structural response uncertainty is slightly increased and it is observed that the COV of the inter-story drift can be highly increased for a specific earthquake. Taking into account that repeated earthquakes have occurred at brief intervals of time, this study also examines the structural response of an already deformed frame subjected to a subsequent ground motion under input uncertainties. Therefore, the frame is subjected to two repeated earthquakes, i.e., combining the previous single ground motions. The results indicate that the material uncertainty does not seem to affect the inter-story drift variance, while the mass uncertainty does. However, more earthquake scenarios are to be examined, since the proposed framework can be easily applied for probabilistic studies of structures subjected to single and/or repeated earthquakes under input uncertainties.

Contributors:
Conference Title:
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.



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 Record created 2017-01-18, last modified 2017-01-18


Original version of the author's contribution as presented on USB, paper 1039.:
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