Defining pinned vs welded connections

Hi,

I'm working with Diagrid structures for my research project and am modelling them thorugh Karamba. How do I know what exactly are the connections being assumed when I model the diagrid structure in Karamba? Is it welded by default since it's input as an exploded set of lines? And how do I assign them as pinned or welded connections?

This is the Karamba layout for modelling the diagrid:

Another question regarding the results obtained through modelling. When I increase the angle of the diagrid (an adjustable parameter grouped in red in the GH file), the resulting maximum nodal displacement (also grouped in red in the GH file) decreases.

Based on how a diagrid's supposed to perform, increasing the angle of a diagrid (to the horizontal) should be causing higher tip displacements, but Karamba's giving me results to the contrary. My supervisor agreed this doesn't look right as well. Why might I be getting results like this from Karamba? Here's a screenshot of the Maximum Nodal displacement panel:

I have also attached the Rhino & Grasshopper files I'm working on. Appreciate any help and feedback regarding my problems! I can post up more screenshots if needed.

Attachments:

Example.gh, 52 KB
20150822_Model.3dm, 29 KB

Replies to This Discussion

Permalink Reply by jjsolly on October 1, 2015 at 3:47am

Initial status is a fully fixed connection unless you tell the software otherwise through releases or turning off bending capacity of the element.

Permalink Reply by Sabeeshan Kulenthiran on October 1, 2015 at 4:04am

Hi jjsolly, thanks for the reply.

Is the bending capacity turned off by connecting the element to a ModifyElement component and setting the Bending-plug to false? Or are there alternative/better ways to do this?

Permalink Reply by Karamba3D on October 4, 2015 at 10:30am

Using the ModifyElement component is the way to switch off the bending stiffness of beams and turn them to trusses.

Regarding your unexpected results: I could not run your definition because I do not have the necessary plug-ins installed. Could you send me a reduced example that shows the same behavior but without using the plug-ins?

Best,

Clemens

RSS