Does scaling the earthquake records affect the frequency content?
By Scaling down the PGA of a specific earthquake record, the ratio of PGV/PGA remains the same. But yes, low PGA value will offer less acceleration and velocity components of the earthquakes.
so my suggestion to you is:
1. Use the earthquake records, which have less PGV/PGA ratio, of the order of 80-100 cm/s/g
2. Normalize all the earthquakes and scale them down to a less PGA value, e.g., 0.2g.
I do not think that the PGA will only affect the structure to cross the elastic limit. I would say the moment the frequecy contents of the earthquake lays nearby the natural frequencies of the structure will cause the structure to cross the elastic limits. In scaling if you are multplying the whole time history data by a factor should affect on frequency contents.
If the record meets the criteria it is copied into a “bin” of motions that will be used ... However, if the criteria are not met, REXEL will scale the earthquake motion ... Other parameters affect the suitability of an earthquake for scaling and relocation. Distance from epicentre, frequency content, and type of faulting that initiated.