Checking the Fidelity of the Input PSD curve Using Ansys Mechanical — Lesson 2

Random vibration analysis is intended for scenarios where the vibrations are not deterministic, i.e., random in nature. Hence the input of the random vibration analysis is probabilistic and is in the form of power spectral density (PSD). While input PSD curves are often provided based on engineering specifications or criteria that must be met, providing high-quality PSD input is critical for getting accurate random vibration analysis results. In this video, we will help you understand how to input the PSD curve, check its fidelity, and improve the curve if needed.

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0:00 - Intro
1:48 – Time history and generating input PSD in frequency domain
2:19 – Random vibration excitation options
5:00 – Modal analysis
7:30 – Random vibration analysis results interpretation (meaning of 1,2,3 sigma results)

[Yeh.A]

Thank you for your this video.
What do you mean by order of magnitude ?

[cristobalsanchez]

Or use as Seismic Analysis for Civil engineering.

[andreykoschey]

Thank you for this video. I have a question. I try to get a displacement of a structure in PSD Analysis. Could I use somehow a measured data from acceleration sensor? By means of fast fourirer transformation i got a acceleration in frequency domain (G^2/Hz) in 3 axis . How could I import this data in ansys?

[yiranli]

For the input PSD profile, as you mentioned, it is averaged square profile. My question is, I don't see you provide/define the variation of the input profile. Is Ansys having some assumption on the variation level? Thanks!