Radius Bridging Issue
Radius Bridging Issue
(OP)
I need your help
Now i am struggling with radius bridging issue on ramp down area of C type as follow

This part is made by hand layup using CFRP fabric prepreg.
Now what i am trying is to enhance consolidation by applying compation for each ply.
Each compation time takes around 10minutes under -28inHg.
I don't know if what i am doing is right or not.
Please give your advice regarding radius bridging issue.
Thank you
Now i am struggling with radius bridging issue on ramp down area of C type as follow

This part is made by hand layup using CFRP fabric prepreg.
Now what i am trying is to enhance consolidation by applying compation for each ply.
Each compation time takes around 10minutes under -28inHg.
I don't know if what i am doing is right or not.
Please give your advice regarding radius bridging issue.
Thank you





RE: Radius Bridging Issue
Often the best technique is to tack the prepreg down on one side of the radius and create a bulge in the fabric that mirrors the radius. Then tack it down on the other side of the radius before pressing the bulge into the radius. This insures that there is enough material between the tack-down points to conform to the radius without requiring ply slippage to prevent bridging. Doing this to excess will cause wrinkles in the fabric during cure.
The key principles to bear in mind are that fibers do not stretch, they can be compressed slightly by increasing the waviness in the weave, fabric can stretch on the bias by scissoring and causing a corresponding compression on the orthogonal bias, and that ply-slippage is often more limited than might be hoped.
RE: Radius Bridging Issue
Compositepro Thank you very much for your sharing valuable information.
Could you please check below article?
this article said that "Fibre bridging may be reduced by using rollers to press the fabric into the corner or by incorporating slip-lines into the layup. However, especially in the latter case this will complicate the layup and increase manufacturing times"
http://aerospaceengineeringblog.com/autoclave-vari...
Do you have any idea of using roller to reduce radius bridging?
Thank you
RE: Radius Bridging Issue
RE: Radius Bridging Issue
RE: Radius Bridging Issue
RE: Radius Bridging Issue
Angle is 172degree, Total plies are 44plies and this material is CFRP fabric
this part is cured in Autoclave.
Dear. Compositepro and cpinz
just before, I got a good result by adding addtional filler plies to radius area.
I will keep posting when other result comes out.
Thank you all.
RE: Radius Bridging Issue
What is the tool material? are you getting excessive tool expansion during heat up?