How to defined Beam-Joints in Java or Python?

Hello there, I got troubles on setting up the joints conditions in Java. The Karamba HackersGuide only provide a simple example on how to set up the single beam model. If the condition became more complex, for example, a group of beams, can I use Karamba.CrossSections.CroSec_Joint to defined the joint conditions?

I found the CroSec_Joint is the inherited class from CroSec which has 12 extra variables that define the joint condition. However, the CroSec class is different from the feb.Beam3DCroSec which used for setting up the structure model.

Great appreciate if anyone can give suggestion how to use it. Thanks.

Replies to This Discussion

Permalink Reply by Karamba3D on August 8, 2015 at 12:32pm

The C#-part of Karamba 1.1.0 realizes joints by adding springs at the start- or end-node of beams in the C++ model. Rigid connections between element degrees of freedom are implemented using large stiffness values.

Best,

Clemens

Permalink Reply by Yutao Song on August 10, 2015 at 9:36am

Thanks for replying, Is it means that in Karamba analysis, the default settings of the joints are defined as the infinite large stiffness spring, which won't deform during the displacement analysis?

Regards

Permalink Reply by Karamba3D on August 10, 2015 at 12:06pm

By default no springs are added at the ends of beam elements. In case of hinges the fixed degrees of freedom of the joint are assigned a stiffness of 100000 times axial beam stiffness. A value too large would lead to numerical difficulties when calculating the deflections.

Best,

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