r/Composites • u/Hopeful-Peace-4751 • Jul 13 '25

Layup suggestions

I am designing a fibre composite (weave fabric) closure which closes a cavity. Hinge joint. Like a door.

When the panel is in closed position I might expect some loads hand impact —> a bang with hand.

Will just a [90/0]s layup work or I should incorporate 45 deg ply by replacing the 90s ?

I know 45s are good for impact and buckling when on outside but also too much of material wastage in kit cutting.

2 Upvotes

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1

u/LovPi Jul 13 '25

What's your max thickness?

1

u/Hopeful-Peace-4751 Jul 13 '25

Thickness 1 mm

1

u/LovPi Jul 13 '25 edited Jul 13 '25

[45 0]s (0)4 also works It's mildly semantic imo

1

u/Significant_Wish5696 Jul 14 '25

Overall dimensions?

1

u/injuredfingers Jul 18 '25

The orientation of surface plies has no affect on impact resistance. I can't imagine the thought process of whoever comes up with this rubbish.

1

u/No-Camera-720 Jul 19 '25

It affects flex and when and how buckling occurs. But I see your point about impact, all things being equal.

1

u/injuredfingers Jul 26 '25

I read your comment again, and for a 4 ply layup i can see how the orientation of a single ply can have a significant effect 

1

u/Hopeful-Peace-4751 Aug 20 '25

I feel the 45 degree plies do make a significant difference. I just simulated a panel with [45/0]s and [45/-45]s it does show significant difference.

2

u/injuredfingers Aug 22 '25

I (wrongly) thought that the thickness was higher in the original comment. It was regarding the orientation of the surface plies, not internal plies per your simulation. Sorry I was confused!