Utilization component reports "MaxValues"

Grasshopper Karamba3D
1

Hello
I’m in a situation where the utilisation values are not returning numbers but “MaxValues”.
What is the cause of this?
is this “MaxValues” indicated every time we are in class 4 ? I’ve never seen that before.

image
image1040×730 73.7 KB

Thanks

edit: it seems that it’s because the model wasn’t correctly defined. I had supports whose rotation plane was incorrectly defined, but surprisingly no errors in the “Assemble”. A bar did not appear in my “ModelView”, and whatever the load value, OptiCross returned the largest section with a “MaxValues” indication.

2

Hello @Jacques,
the ‘MaxValue’ is not connected to the warning regarding class 4 cross sections. ‘MaxValue’ can result in case of zero material strength or zero cross section resistance (e.g., A = 0, Iyy = 0…).
It would be interesting for me to know the details regarding the incorrectly defined rotation plane so that I can add a corresponding check. It would be great if you could you post a small example which features the bug.
– Clemens

3

thank you
that’s what I thought, I had a bar that didn’t appear after the “Assemble”.
There was a problem either with the rotation of the supports or with the rotation of the bar.
I’ve completely reworked the approach to defining the supports so that it works. Maybe it was a problem of tolerances…

I’ve attached the gh file internalising the data, but it might not be easy to understand.

To help you understand, the lines defining the bars are as follows (168lines):

image
image1049×374 97.9 KB

these 168 lines do appear in the assembly and also in the model output after OptCross, but they no longer appear in the modelView

image
image948×416 116 KB

image
image920×312 179 KB

I get an error indicating that some of them are in class 4 or cannot be optimised, and returns a MAx-VAlues in the utilisation rates

I don’t know if this will really help to understand whether there’s a bug or not.
MaxValues.gh (74.5 KB)

4

Hi, we have been looking at this and it might be a bug when there are multiple models which are disconnected from each other. This will take us some time to resolve this. I would suggest to either connect your model with beams or split your model into separate smaller models if you need to solve this now.

5

Hello
ok thanks for the investigation
But I don’t understand your comment, in my example I only have one model

Or do you mean that this is the case when I have separate bars (not connected to each other and with their own supports) in a model?

6

It is one data structure, but the beams are not connected meaning that there are “multiple” models in your setup.

7

hello @keuj.84,
I think the problem in the definition ‘MaxValues.gh’ is rooted in the input of ‘Null Planes’ for the supports:
MaxValues - mt_cp.gh (34.9 KB).
I will add a corresponding warning in K3D so that one gets a more informative response.
– Clemens

8

thank you both for these clarifications