Hinge Connections

Hello, I am an architect and I need to work with hinge connections. I did not understand the user manual, I don’t know advanced structural engineering terms, I can’t find an explanation or tutorial on this. The “joint” components are too complex. I don’t even understand if the beam joints degrees of freedom work in the same way with that of supports (In supports, when we click on them, they are fixed, but in joints, does clicking also make them fixed or not?) I try many options but it does not work as a hinge supported structural system. It collapses in any type of joint definition, and when I only click on the rotation degrees on beam joints, it looks ok, although I have an unstable structure. Can someone advice a link or a simple explanation for this? The user manual is too complex for an architect.

Hi @oyku.acican, the default setting for all connections in Karamba is that they are rigid connections. With the BeamJoints component you can define a degree of freedom by simply clicking on the node to activate it.

The example here shows a joint which is defined for all 3 translational and rotational axes.

Hello, I plugged the “point” output from “line to beam” into the “geometry” input of beam joints component, and I clicked on the rotation on y, so now it should be hinged connections?. In that case, a box structure should not be stable without diagonal braces. However, Karamba gives the same result for a braced box and unbraced box. I should prove its instability with the Karamba result but I can’t. Normally, when something is really wrong, Karamba gives a result with extreme deformation. In case of a box structure, it just shows a regular deformation as if it will be able to stand. I also upload my GH file with my questions embedded. I am a researcher on structural education for architecture students, and I need urgent help, because we use Karamba and the students should gain valid results. Thank you for your help.Karamba Question.gh (31.6 KB)

Hi @oyku.acican,

it seems to work as expected in your definition. You can see that when the joints are defined, the Analyse component turns orange and informs you that there rigid body modes in the system. If you use the Eigenmodes component you can see how the elements are moving. When you analyse the setup with the diagonals, there are no longer these issues in your definition.

Yes I can see the instabilities in Eigenmode visualizations. Thank you very much for your consideration and help.