Quasi-static analysis with Explicit

[g.alshamsi]

Hello,

I have a conceptual question.

Why is the frequency (or period) of the first mode used as an estimate to determine the velocity or time step of quasi-static analysis using the explicit solver? The theory states that the dominant response of a quasi-static analysis will be the first structural mode, however I'm having trouble understanding the concept in simpler terms.

Cheers!

 

[FEA way]

The first natural frequency corresponds to the longest vibration period of a structure. The load has to be applied at a significantly lower rate (at least 10 times longer than that lowest vibration period) to make the process slow enough to avoid dynamic effects and thus obtain a quasi-static solution.

 

[g.alshamsi]

Got it, thanks for the explanation.