Sorry to dig up an old ghost here. But my team is running into this as well on Inventor 2017. Did this issue ever get resolved? Has the Frame generator analysis tool been improved to support analysis of curved frame members?
Thanks,
Stephan
Gilberto Binga
Engenheiro Mecânico - Engenheiro Mecatrônico
deLearning - YouTube Channel
Facebook | LinkedIn
LOUCO POR AUTODESK
A resposta resolve seu problema? Ajude outros usuários marcando "Aceitar como Solução"
Does the answer solve your problem? Help others checking "Accept as Solution"
Curtidas são apreciadas caso tenha gostado da informação
Likes are appreciated if you liked the information.
Forgive me asking this again. But from what I've read Frame Analysis doesn't mesh and use FEA. It simply uses bending beam equations. (or have I got that wrong) As such it doesn't need to know how the break up the arc, it just needs to know the radius of the frame line, the cross section of the member, the loads and constraints, and correct equation for a curved member.
Correct. The Frame member itself only provides the section properties to the analysis tool — no meshing.
@michael_r_gerrard wrote:
...It simply uses bending beam equations. (or have I got that wrong) As such it doesn't need to know how the break up the arc, it just needs to know the radius of the frame line, the cross section of the member, the loads and constraints, and correct equation for a curved member.
I have highlighted several words in your description above.
What is the "radius of a line"?
What is the "correct equation for a curved member" (any member - you can make one up)?
If possible, refer to beam analysis equations in the Machinery's Handbook or on-line resource so that I can reference the appropriate equation.
AFAIK - there are three different mathematical analysis techniques in Inventor stress analysis:
1. Mesh
2. Thin Feature
3. Beam (straight line members)
Each of these is appropriate analysis technique dependent on the geometry.
The CADWhisperer YouTube Channel
I'm at home so it's not that straightforward for me to put a screenshot of what i'm talking about up. But if you could picture a 2D sketch of a straight line, with an arc on the end. This forms part of a wider structure, but for now, it's all we need to consider. You can use this sketch to create a frame with Frame Generator. FG will break the arc into segments of straight lengths, but the underlying sketch still has a true arc, which is a section of a circle with a known radius.
A very quick google of "Curved Beam Calculation" led me to this http://courses.washington.edu/me354a/Curved%20Beams.pdf
Which is, I ASSUME, the type of calculation going on in the background on Frame Analysis. Just for straight beams.
It's quite possible that answer to the above assumption is simply "No that's not what it's doing in the background"
Or, it might be the case that it is the same kind of equation, but adding this it would break the way it currently Frame Analysis works and need a ground-up redesign of some matrices that are in the "Hard Math Problem" section of engineering.
Either way, I'm out of my depth.
Time to consider workarounds.