convergence issue

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lvy
Posts: 26
Joined: Tue Dec 14, 2004 8:22 pm
Location: Shanghai, China

convergence issue

Post by lvy »

Hello, everyone.

I performed a transient analysis. When I take P-delta effect into account, the analysis stop for convergence issue. But the analysis could achieve convergence leaving P-delta effect alone. How to improve the convergence of the analysis?

Thanks!!
JunLi
Posts: 5
Joined: Fri Jun 18, 2004 1:34 am
Location: China

Post by JunLi »

May be the analysis object collapsed before the whole transient analysis was achieved. So you should stop it as the deformation of the analysis object reaches maximum.
fmk
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Location: UC Berkeley
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Post by fmk »

P-Delta typi results in more forces in the elements of the model and it will
also increase the number of iterations for convergence .. corotational will be even worse if the model experiencing large displacements .. is the convergence problem global or local?
lish hit
Posts: 20
Joined: Thu Nov 11, 2004 8:00 pm
Location: HIT

re

Post by lish hit »

It’s a good question to discuss,in my analysis(take account P-Dalta),if the convergence problem ids global,i.e.the displacement is always increase in one direction.Either I use smaller dt or other arithmetic,is failed to convergence also,does anyone kown some methed to improve the problem(I mean make the analysis can process a little more time)? And does the force-based element can give preciseness result in so large displacement?
lish hit
Harbin Institute of Technology
e-mail:leeshhit@163.com
Structural nonlinear dynamic analysis,
structural simulation
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