The validation is done based on a time scaled ground motion (response of shake table). However, for this validated numerical model, do the time histories (to be used for incremental dynamic analysis) need to time scaled based on the similitude laws for further analysis?
Note: time histories for IDA are obtained by matching the target response spectrum of the numerical model.
To my understanding of your question, I feel 'No', if you are talking of scaling the duration of motion (and not intensity). Rather you may identify key ground motion parameters that govern response. This is somewhat judgmental. Scaling should focus on these parameters.
Numerous works of Prof. Nicos Makris and his co-workers who first introduced dimensional analysis to establish remarkable order in in seismic response shall be very enlightening for your problem.
Dear Prof. Roy,
Thank you for your response. Yes, I meant scaling the duration of the time history. The reason why I got confused is because the ground motion time history used for the shake table experiment is a time duration scaled version of the original time history (based on the scaling ratio between the prototype structure and the model tested). Therefore, the response of the shake table is also a time duration scaled time history which is used for the numerical analysis to validate the numerical model.
Since, I'm calculating a target response spectrum based on the numerical model, and extracting ground motion based on this target response spectrum (also scaling the ground motions - spectral acc. only), I guess there is no further need for scaling the duration of time history as this acts as a new analysis problem.
Are you also arriving at the conclusion 'No' based on this thought?
I could not follow the need of using duration scaled motion in experiment. This perhaps complicate the problem unnecessarily. If the experiment is already over, model structure under the scaled excitation may be directly used at this point. For a guideline on scaling for shake table experiment, the following report may be useful:
Hachem, M. M., Mahin, S. A., and Moehle, J. P. (2003). “Performance of circular reinforced concrete bridge columns under bi-directional earthquake loading.” Pacific Earthquake Engineering Research Centre Rep. No. PEER 2003/06., Univ. of California, Berkeley, CA.
By the statement: 'Since, I'm calculating a target response spectrum based on the numerical model, and extracting ground motion based on this target response spectrum (also scaling the ground motions - spectral acc. only), I guess there is no further need for scaling the duration of time history as this acts as a new analysis problem.', I understand that the numerical analysis is no longer intended for validation purpose. In that case, you are right. This is a popular strategy. Yet, scaling ground motion on the basis of spectral acceleration, i.e., multiplying motion by a factor (>1 or
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