Maximum Number of Integration Points

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salehi
Posts: 49
Joined: Wed Aug 01, 2012 3:57 am
Location: University of Colorado - Boulder

Maximum Number of Integration Points

Post by salehi » Tue Dec 22, 2015 8:52 am

Hello everyone,

I have developed a force-based beam-column element which needs large number of integration points to yield objective response. When I use more than 20 integration points, however, OpenSees stops working, without displaying any error. May I possibly know what should be modified, please? Thanks in advance.
Mohammad Salehi
Graduate Research Assistant
PhD Student - Structural Engineering and Structural Mechanics
University of Colorado at Boulder

fmk
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Re: Maximum Number of Integration Points

Post by fmk » Wed Dec 23, 2015 3:42 pm

is this your own force-beam element or some special integration rule that the force beam element is using?

salehi
Posts: 49
Joined: Wed Aug 01, 2012 3:57 am
Location: University of Colorado - Boulder

Re: Maximum Number of Integration Points

Post by salehi » Wed Dec 23, 2015 11:06 pm

Hello Dr. McKenna,

Thanks for your quick reply. It is a force-based beam element that I have developed and it uses the OpenSees beamIntegration classes. Actually, I could resolve this problem myself.

For those who may encounter similar issue, looking at some of the beamIntegration classes, I found out that some of them, such as Gauss-Lobatto and Newton-Cotes, provide the IP locations and weights for up to only 10 IPs. As a result, I modified those classes and now I can get the locations and the weights for up to 20 IPs for Newton-Cotes method and unlimited number of IPs for Gauss-Lobatto. I also had to replace the fixed array secX in the function setResponse() with a dynamically allocated array with the arbitrary size of numSections.
Mohammad Salehi
Graduate Research Assistant
PhD Student - Structural Engineering and Structural Mechanics
University of Colorado at Boulder

linguan118
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Joined: Sun Oct 03, 2010 11:36 pm
Location: Hong Kong

Re: Maximum Number of Integration Points

Post by linguan118 » Sat Mar 19, 2016 7:07 pm

Is there a big difference when you use 10 or 20 ips? For hardening behavior, I guess there is no much difference. For softening behavior, you will not get objective result using more ips, plastic hinge element will give objective results.
Research Assistant Professor, The Hong Kong Polytechnic University
guanlin@polyu.edu.hk

salehi
Posts: 49
Joined: Wed Aug 01, 2012 3:57 am
Location: University of Colorado - Boulder

Re: Maximum Number of Integration Points

Post by salehi » Thu Apr 14, 2016 9:08 pm

Linguan:

Yes, it makes difference for our element, which uses gradient nonlocal theories to provide objective responses for the softening part. You may find it here, if interested:

http://0-ascelibrary.org.libraries.colo ... 89.0001083
Mohammad Salehi
Graduate Research Assistant
PhD Student - Structural Engineering and Structural Mechanics
University of Colorado at Boulder

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