Maximum Number of Integration Points

[salehi]

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.

[fmk]

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

[salehi]

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.

[linguan118]

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.

[salehi]

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