Talk Composites - The Forum for Advanced Composites
Back
Login
Register
Login
Register
Home
»
Advanced Composites Forum
»
General Composites Discussion
»
Stiffen a pipe
Stiffen a pipe
Post Reply
Like
4
Stiffen a pipe
View
Flat Ascending
Flat Descending
Threaded
Options
Subscribe to topic
Print This Topic
Goto Topics Forum
Author
Message
Massimiliano
M
Massimiliano
posted 3 Years Ago
ANSWER
HOT
Topic Details
M
Group: Forum Members
Posts: 167,
Visits: 1.1K
Hi, I have the structure below which, under solicitations, is bending a bit towards the direction of the red arrows.
Pipes are 40mm diameter.
I was thinking about moulding two half pipes composed mostly of several layers of unidirectional carbon tape and then glue with mma the half pipe to the existing pipes (along the orange lines).
The layup I am thinking is 10x layers of 50mm wide 650gm2 carbon unidirectional tape, alternated with some 50mm wide plain carbon tape.
What do you think about the idea and the layup schedule?
Also, maybe adding a 2 mm pvc core in between would help? I am just worried that the shear force could cause the two carbon frames to slip on the pvc core, so maybe a not cored layup would be better?
Reply
Like
4
GO
Merge Selected
Merge into selected topic...
Merge into merge target...
Merge into a specific topic ID...
Open Merge
Threaded View
Threaded View
Stiffen a pipe
mporta71
-
3 Years Ago
I think a much better approach would be to have a shear web in-between at least two of the tubes. either made from carbon with a plus minus 45° layup or arguably just from steel welded in. This way.....
SleepingAwake
-
3 Years Ago
Yeh it looks like a terrible design for rigidity in that plane, it's got 0 bracing for it. Must be quite strong in the opposite direction! But yes, the solution to this is more about bracing the...
Hanaldo
-
3 Years Ago
Hi, I should have specified that it is not stainless steel unfortunately but aluminum, this is one of the reasons it is bending and also why I thought about a thick carbon shell on the existing pipes...
mporta71
-
3 Years Ago
Doesn't make a great deal of difference, the issue is still the geometry of the structure. It needs horizontal bracing or gussets. Really the big problem with it is the way they have placed bent tube...
Hanaldo
-
3 Years Ago
Totally agree on the bad design but unfortunately I bought it already made. The aluminum is powder coated, I read that mma bonds very well to powder coated so I thought to just do a proper cleaning. ...
mporta71
-
3 Years Ago
If possible you might consider to add some plates to the sides, at least around the knot section in the middle. They would take the shear forces and would change the stiffness of the structure...
oekmont
-
3 Years Ago
This could be doable too, thank you
mporta71
-
3 Years Ago
I contacted the guy who originally made it and he is suggesting this addition (highlighted in red) made out of ss and bolted to the existing structure. What do you think?
mporta71
-
3 Years Ago
the plates on the sides was exactly what i was referring to with the shear webs, which would be far superior to the proposed tube that is bolted on.
SleepingAwake
-
3 Years Ago
Thank you, I can't imagine really what you mean. If you have any spare time, would you mind drawing on my picture your suggested idea?
mporta71
-
3 Years Ago
This extra beam is -like the structure itself- not made with mechanical expertise. There are several reasons why the beam will not change the stiffness as much as a similar amount of material used in...
oekmont
-
3 Years Ago
Yeh agree with Oekmont on all points. Hadnt really considered bolting anything - I am used to working with roll cages in race cars where bolt-in is far inferior to weld-in. It would be here too, but...
Hanaldo
-
3 Years Ago
If you add plates to the marked plane on both sides of the structure, and bolt them every few inches the stiffness should improve quite much. if you only find shorter plates you might just cover the....
oekmont
-
3 Years Ago
Thank you!!!
mporta71
-
3 Years Ago
Post Reply
Like
4
Similar Topics
Post Quoted Reply
Reading This Topic
Login
Login
Remember Me
Reset Password
Resend Validation Email
Login
Facebook
Google
Explore
Messages
Mentions
Search