High strength tube for roller

[Sonu]

Respected all,

I am Sonukumar Sharma from Maharashtra India.

we are working on high rpm CF roller (8000rpm), length - 1100mm, OD- 42.5mm, ID - 30mm.

we have made tube ( web angle 14 degree, with intermediate hoop layer ) through filament winding but we couldn't succeed as deflection (required <0.2mm under 25kg load) at the centre of tube was 0.6mm under 25Kg load. 

could you help us.

[John Kimball]

6 hours ago, Sonu said:

Respected all,

I am Sonukumar Sharma from Maharashtra India.

we are working on high rpm CF roller (8000rpm), length - 1100mm, OD- 42.5mm, ID - 30mm.

we have made tube ( web angle 14 degree, with intermediate hoop layer ) through filament winding but we couldn't succeed as deflection (required <0.2mm under 25kg load) at the centre of tube was 0.6mm under 25Kg load. 

could you help us.

Welcome to the forum!

Your situation may require some redesign if possible.

The first thing you can do is to eliminate the 14 degree winds and replace as many plies as possible with 0 degree fibers. You don't want to use 100% 0 degree, as this will increase kinking potential. This can be difficult with filament winding, but not impossible.

If that doesn't work, then you will need to increase wall thickness as much as possible, as stiffness in a tube is increases as the tube diameter increases and wall thickness increases.

[Sonu]

17 minutes ago, John Kimball said:

Welcome to the forum!

Your situation may require some redesign if possible.

The first thing you can do is to eliminate the 14 degree winds and replace as many plies as possible with 0 degree fibers. You don't want to use 100% 0 degree, as this will increase kinking potential. This can be difficult with filament winding, but not impossible.

If that doesn't work, then you will need to increase wall thickness as much as possible, as stiffness in a tube is increases as the tube diameter increases and wall thickness increases.

Sir,

Thank you for your reply.

1. In this case can we go roll wrapped tube.

2. Any suggestions on resin and curing temperature.

3. We used 240Gpa (35msi) 12k fibre.

 

[John Kimball]

On 8/12/2023 at 12:05 PM, Sonu said:

Sir,

Thank you for your reply.

1. In this case can we go roll wrapped tube.

2. Any suggestions on resin and curing temperature.

3. We used 240Gpa (35msi) 12k fibre.

 

Roll wrapped is a good option as it is a bit more precise on the OD. For fabric prepreg or unidirectional prepreg on a roll wrapped tube, and to get better deflection properties, your best bet is intermediate modulus fiber with at least a 250°F cure resin. With roll wrapped, your best bet is 3K fabric and 150gsm unidirectional. 

[Sonu]

On 8/15/2023 at 9:47 PM, John Kimball said:

Roll wrapped is a good option as it is a bit more precise on the OD. For fabric prepreg or unidirectional prepreg on a roll wrapped tube, and to get better deflection properties, your best bet is intermediate modulus fiber with at least a 250°F cure resin. With roll wrapped, your best bet is 3K fabric and 150gsm unidirectional. 

Sir, we made one sample tube by roll wrapped, we used intermediate module (390Gpa) but, couldn't achieve the required results.

We can't increase outer diameter which is 42.5mm.

Any other solution which we can try?

Is there any concept of pre stressing of CF tubes?

 

 

[John Kimball]

6 hours ago, Sonu said:

Sir, we made one sample tube by roll wrapped, we used intermediate module (390Gpa) but, couldn't achieve the required results.

We can't increase outer diameter which is 42.5mm.

Any other solution which we can try?

Is there any concept of pre stressing of CF tubes?

 

 

You may need to increase the percentage of 0º fibers to get what you need. If you can’t increase the outer diameter, can you decrease the Inner diameter? Also you may want to consider a post cure to increase the properties of the resin. The post cure may take 8-12 hours to perform.

Also be sure to apply proper pressure when roll wrapping. Proper consolidation is key to maintain proper mechanical properties.

I’m assuming that you are referring to prestressing like a span bridge beam. The only way to properly do that with composites is to create a mold with that prestressed shape in it. That would make everything more difficult to do.