G rms Value for the Given PSD Profile

Is it possible to understand the G rms (Root Mean Square Acceleration) value for the given PSD profile?

G rms is a relative feel. For example, if you have cantilever beam subjected to 1000 N tip load in case-A and in case-B the same cantilever subject to 5000 N tip load. Now you will get a feel that Case-B loaded heavier than Case-A.

Grms is used to qualitatively access both the Input PSD and Response PSD (RPSD). For an example, you have bracket mounted on a chassis subjected to base excitation, which is specified in terms of PSD and your objective is to access a bracket design through PSD analysis. Let say, this bracket is to be accessed for two different road conditions 1) Smooth Highway Road < PSD-A input curve> 2) Rough Off Road.

For both the PSD-A input curve and PSD-B input curve, G rms-A and G rms-B can be calculated respectively. More the G rms heavier the loading, again; it's a relative feel.

Like for input PSD, from the RPSD also G rms can be calculated. For an example; for ONE give input PSD profile, you want to ascertain 2 different bracket design. After doing PSD analysis for both the brackets you will give two different RPSDs one from each bracket. Now you can also calculate two different G rms (output / response). Among their Output G rms values, higher G rms bracket qualitatively tells that there is more dynamics magnification, compared to other bracket.

Just with the G rms value, an engineer cannot understand anything, more details should be accompanied along with G rms.