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geometry imperfection and RESTART card after Riks analysis

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jcmbl

New member
Oct 22, 2004
31
Hi all,

I am having some dificulties in understanding some issues.

1. I am having a beam model, with thickness variable along its length. The beam is subjected to an offset load (e.g., 0.3% of the beam length). the question is, if I want my beam to exhibit large displacements (elastica), should I introduce the imperfections from a *Buckle analysis? Or it's just enough that I have the offset load. I tried both cases, and the results of maximum displacement on the beam are almost the same.

2. I am interested in finding solutions of exact values of the load. If I'm using Riks with LPF=1 (no point in using more than 1), and printing the nodes, do I get the final solution?
But, the documentation suggets that for an exact solution I have to restart the Riks step with a non-Riks one, using *Restart - End Step card, using an appropriate force magnitude. But I have already used a LPF=1, and I don't wanna go further with the load.
I am interested in finding the deflected shape after each increment. And, what have I plotted at the earlier point? Isn't that the real deflected shape?


How can I assess this problem?

I would appreciate any help from you, for either of the questions.


Regards,

Jm
 
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