STRUCTURAL PROFILE - LENGTH CALCULATION

I HAVE TO CALCULATE LENGTH OF A STANDARD STRUCTURAL PROFILE.

HOWEVER BOTH EDGES ARE CUT SUCH THAT THEIR SURFACES ARE NOT PARALLEL TO EACH OTHER.

ASSUMING THAT CROSS -SECTION AREA OF THE PROFILE IS KNOWN HOW CAN I CALCULATE THIS PROFILE (BREP)?

THNX

Replies to This Discussion

Permalink Reply by Dedackelzucht on July 26, 2011 at 4:24am

hey,

this works maybe :-)

Best Regards

DeDackel

ps.: please stopp writing in big letters, kind of stressing :-)

Permalink Reply by Chris Tietjen on July 26, 2011 at 4:41am

You question seems a little bit ambiguous. I'm not sure how cross-section area comes into play for calculating length. Here's an idea on it.

Chris

Permalink Reply by Firat Aydin on July 26, 2011 at 6:14am

THNX FOR YOUR APPROACH CRIS. BUT I ALREADY FIGURED OUT IT IS NOT WORKING. THE SHAPE I HAVE TO DEAL WITH IS ANY STANDARD I SHAPE OR HOLLOW CROSS SECTION. HOWEVER IF I DIVIDE VOLUME WITH CROSS SECTION IT DOESNT GIVE THE LENGTH SINCE UNPARALLEL SURFACES ARENT INCLUDED. I HOPE MY SNAP WILL HELP YOU TO HELP ME.

I MUST MATERIAL REQUEST IN LARGE QUANTITIES ACCORDING TO A RHINO MODEL. PLS HELP!

Permalink Reply by Dedackelzucht on July 26, 2011 at 6:18am

mh?

to me it seems that Chris got it. If you combine my file with his file you can also get the length of profiles which are not oriented in x or y direction. Why is it not working?

Best Regards

DeDackel

Permalink Reply by Firat Aydin on July 26, 2011 at 6:38am

HOW? COMBINE? I AM A CRAWLING INFANT ON FOURS AT GRASSHOPPER. PLS GIVE ME MORE UNDERSTANDABLE RESPONSES. CLOCK IS TICKING FOR ME :(

AND IF POSSIBLE IT MUST WORK ONLY ONE CLICK. ( WHEN I SELECT BREP LENGTH MUST BE CALCULATED.)

ACTUALLY I WAS JUST CLOSE TO IT. LET ME TELL HOW I DID IT. I EXPLODED IT TO POINTS. I CALCULATED DISTANCES BETWEEN EACH POINT. HOWEVER IT IS GIVING A COUPLE OF mm FAILURES SOMETIMES.(BECAUSE OF MOST OPPOSITE CORNERS)

I HOPE MY WAY CAN INSPIRE SOMETHINGS TO YOU.

PLS HELP. I HAVE TO CALCULATE MAY BE MILLIONS OF SUCH THINGS AND GIVE PURCHASE ORDERS.

Permalink Reply by Danny Boyes on July 26, 2011 at 7:55am

Why is Chris' approach not working? Are your extrusions straight? Here is a shot of essentially the same method but with a dimension added for clarity.

Permalink Reply by Jon Mirtschin on July 26, 2011 at 10:01am

I think Chris has a correct approach, but I don't think his definition works for objects of arbitrary orientation (ie not aligned with X, Y, or Z axis) as I'm assuming will be the case in the desired model.

If I was costing this I would also be using the length of the member before mitres are done (ie aligned bounding box) unless I knew there was exact nesting of different members. Accuracy to within a few millimetres I would also assume is acceptable.

Attached is how I would calculate this length, I'm sorry but I'm running latest grasshopper version (link below) so I think you have to update to open it. Screenshot attached. This method does assume brep longest length is in longitudinal direction (ie no stub members).

http://www.grasshopper3d.com/forum/topics/grasshopper-0-8-0050-deve...