Help for Spring under 'Cross Section'

Hi team,

Hope your day is going okay :blush:

I’m a new parametric design user, don’t know much about data structures. I’m just learning how to set up a simple stick model(like below) and run it with some karamba functions.


This is what I have got so far – the simplest way I found so far, however, it doesn’t register my spring cross section even after inputting it into my line-to-beam function. It doesn’t seem to register both my actual cross section prop and spring which falls under ‘cross section’, or it gives two separate results… Pls find attached tank-4 file.


In my previous trials, I broke element 1 into multiple segments, create horizontal members with stiffness properties signifying the spring stiffness I’m after (see below), however, going down this route, I had to create the triangular distributed load on each element individually using polylinear in beam load. I tried looping through a list of number, to extract each element fr element list based on the index called and its corresponding force fr the list of forces I’ve produced. But it didn’t seem to do what I was hoping it would, while it does loop through the element list through the index called, it doesn’t behave the same manner in the ‘force’ list, but only the first 2 values of the list (see below), I wondered if force only takes in 2 inputs… Anyways, that’s just me sharing what I’d tried, I do NOT think having the element segmented and individually inputting the load for each element is the most efficient way for me down the line, as I have more load cases that I’d have to work that out with…. Unless you can suggest a better way of not having to do that… I previously thought I could have the element for load application and segmented elements to introduce spring separately and the software will somehow be able to work out they’re the same elements, btu I got a separate individual result like what happened for 2 cross section(s). Again, I’m not familiar with tree structures… so maybe I’m not matching them correctly?

I’ve attached tank-3 file for your reference. (59.7 KB) (59.1 KB)

Please let me know how I can move forward. Thank you

Has anyone experienced using spring under ‘cross section’ before?

Any help is appreciated.

Hello @lorrn,
the spring cross section in K3D lets you define a stiffness relation between two nodes (see here).

Currently (version 2) Karamba3D does not offer continuous elastic support for beams. It is on my TODO list but will take some time. As a workaround your approach with segmenting the beam is currently the best option in my opinion.
– Clemens

Hi Clemens,

Thank you very much for your reply :slight_smile: