If I inject an earthquake as stress Sxy at the base of the model as a function of velocity, what sign should it go with? positive or negative?. When the velocity and displacement records of the earthquake present a sinusoidal trend, I imagine that the sign should give the same, but in case of having an increasing function to some sign, should the earthquake be injected through the stress with a positive or negative value?
I think it doesn’t matter, earthquake, is waves, contains both negative and positive components
It shouldn´t really matter, but for sake of finding the most conservative response i would run both cases.