Hose Modeling
Hose Modeling
(OP)
Any tips on how to do the following?
Given: Hose endpoints X,Y,Z coordinates, endpoint tangent vectors, and hose length.
How to construct spline that has minimum strain energy for the constraints given above.
Given: Hose endpoints X,Y,Z coordinates, endpoint tangent vectors, and hose length.
How to construct spline that has minimum strain energy for the constraints given above.





RE: Hose Modeling
Hope this helps...
Regards,
SS
CAD should pay for itself, shouldn't it?
RE: Hose Modeling
If this is a common problem, you may want to look into the 'routing' application.
RE: Hose Modeling
Good point! I wasn't sure what Butelja meant by 'strain energy' so I just "assummed" simplicity would be the best place to start (that, and I've no experience with the routing application, other than to know that it exists)... but ya know what that means!
Regards,
SS
CAD should pay for itself, shouldn't it?
RE: Hose Modeling
The true free shape (absent gravity and hydraulic loads) should be a path that meets the boundary conditions (position, slope, and overall length) while minimizing the strain energy (think energy stored in a spring) of the total hose assembly.
This is really as much a solid mechanics / strength question as it is a modeling question.
RE: Hose Modeling
I'm not quite sure of understanding the solid mechanics/strength issue of your problem, but from what I understood of the geometric constraints you have (both end positions of hose - G0-, both end tangancy - G1 -, and hose length), bridge curve can effectively help you. As Cowski said, the remaining problem is the length. I can't tell you anything about routing as I know as much as Shadowspawn about it, however, a spreadsheet may help you:
- make a bridge curve fulfilling the position and tangancy constraints.
- in the expressions, make the second shape control value equal to the expression of the first one (the default valueis 1) (this is a constraint you may not want though)
- name the bridge curve: Edit/properties (!! do not name the feature only, it won't work!!)
- go to Tools/Spreadsheet...
- extract expressions
- enter the ARCLEN formula in one cell (see the "MASS3D" help file of NX for how the ARCLEN works)
- then, still in excel, make a Tool/Goalseek with the length of the core of the hose as "target value" and all your geometric constraints will be satisfied.
hope that'll help
EVALCURV function in the MASS3D functions may also interest you for your strain problem.
TP
RE: Hose Modeling
TP
RE: Hose Modeling
Tim Flater
Senior Designer
Enkei America, Inc.
www.enkei.com
RE: Hose Modeling
As a disclaimer, I also know nothing about the routing application except that it exists.