Learning Forum

[AR]

Hello,

I have to simulate an earthquake so I modelized a Static Strucutral -> Modal -> Response Spectrum. The Static Structural is to introduce the Gravity acceleration.

1) Does the Rsponse spectrum result take into account the stress due to gravity acceleration from the static analysis?

2) If it is not included, how can I make it take it into account? Do I have to add the value of the acceleration due to gravity to the spectrum of the acceleration on the Z axis? The maximum of my current spectrum has a maximum of 7 m/s^2 so I understand that it is not included, right?

 

Regards

[peteroznewman]

You can solve each one separately then add the stress values together in a Solution Combination.

[AR]

So, the Response Spectrum does not take into account the stress produced by the acceleration of gravity despite having a static structural analysis before the modal, right?

[peteroznewman]

Correct. Response Spectrum does not take into account the stress due to gravity.

If you have a Static Structural solution linked to the setup cell of Modal, which is linked to Response Spectrum, then the STIFFNESS change due to gravity will be taken into account, but not the stress.  The reason is that gravity is a constant value, while Modal only deals with vibrations about the zero position.

[AR]

Ok, thank you a lot

 

Best regards