Hi, Jonathan!
The displacement state that you obtain in /POST1 is the response of structure at an harmonic load with that frequency.
Generaly, dynamic behaviour of a structure could be expressed in time domain or in frequency domain. There is a relationship between the two domains via the Fourier transforms.
Anyway, as rigidity of a structure characterize the response of a structure in a case of a static load, the modal frequencies and mode shapes characterize the response of a structure in a case of dynamic load. In fact, as you probably already noticed every kind of dynamic analysis in ANSYS permitt the use of Mode Superposition Method.
So, the response you get is a combination of mode shapes.
For more details you should read "Harmonic Response Analysis" section of "Analysis Procedures" chapter from your ANSYS Theory Manual and the chapters who describe Harmonic Analysis from your "Structural Analysis Guide".
Of course the best way will be to read some extra material about harmonic analysis (basically every vibration book have one or several chapters in this domain).
Best regards,
Juzz
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Justin Onisoru
Researcher
Romanian Academy
Institute of Solid Mechanics
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