Hi everybody,
When I run a dynamic response using earthquake spectral, I get two chart/figure of my input spectral acceleration (see figures below).
The neutral picture (left figure) give a correct input acceleration, and this is the data used in analysis when I check the listing output.
When looking at the neutral chart, the shape of the curve remains the same as neutral picture. However, the data is somehow different with negative periods and negative accelerations.
Can someone explain why there is this different ? Is this a bug of my SACS version ? I use SACS 12.0.
Thank you in advance,
Anthony