Influence vector for Multiple Support GM

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simonkey
Posts: 27
Joined: Thu Feb 18, 2010 6:15 pm
Location: UC Berkeley

Influence vector for Multiple Support GM

Post by simonkey »

Hello,

How do I assign prescribed displacements at the supports and obtain the resulting influence vector at the structural DOFs?

For now, I would like to obtain these displacements without specifying ground motion files at the supports.

Thanks!
fmk
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Post by fmk »

you assign support displacements using the MultiSupport pattern .. details available in the manual.
simonkey
Posts: 27
Joined: Thu Feb 18, 2010 6:15 pm
Location: UC Berkeley

Post by simonkey »

I have two more questions/clarifications related to influence vectors.

For a 3d model with z axis as vertical, I would like to perform RHA with uniform and bidirectional patterns.

1) For uniform pattern with direction specified in $dir, is the influence vector all ones in the direction $dir and zero elsewhere?

2) From the examples in manual, I understand that we invoke uniform pattern twice for bidirectional, but what is the associated influence vector? Is it sqrt(2) (or ones or neither!) for all dofs in x and y and zero elsewhere?

I'm interested in clarifying this influence vector because I don't want to make a mistake in calculating the modal participation factors.
fmk
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Post by fmk »

1. 1's and 0's

2. 1's and 0's again.
simonkey
Posts: 27
Joined: Thu Feb 18, 2010 6:15 pm
Location: UC Berkeley

Post by simonkey »

Yep. Got it Thanks!
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