I want to make a carbon monocoque Chassis. I will use resin infusion for laminate. Is there any way i can use Aluminum Honeycomb for my sandwitch?

Not in the infusion.  If you tried to infuse a honeycomb all that would happen is the cells would fill with resin and the part would be super heavy!

You can infuse an inner and outer skin then bond in the honeycomb no problem.

Making a seperate inner skin mould can be awkward if you are doing this manually by hand.  If its in CAD its dead easy to do and you can have a new pattern cut from foam by CNC as precise as you like for an inner skin mould.

Probably the simplest way would be to infuse the outer skin. Then bond in your honeycomb. Once bonded, wet lay a thin scrim of glass fibre over the honeycomb to seal it off, then wet lay and vacuum bag the inner layers of carbon.

That way you wont fill your cells with resin, will only need one set of outer skin moulds, and also by vac bagging the inner, you still have a high performance inner skin to match the performance of the outer.

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant

So what is the next best thing to use for core material if i want to infuse the whole sandwich together?

Depending on size and shape, I would suggest 3d core or foam for minimal weight

Thanks for your help guys. Have you any idea which of the two (3d core or foam) will result to better weight to strength ratio if I use the same carbon cloth (type and quantity). Thank you in advance. 

Foam will usually result in a lighter part, so it should produce a better weight to strength ratio.

Before anyone proves me wrong, of course it all depends on the shape of the part you want to build, and the direction of the forces acting on it. If the thickness doesn't matter, a foam core can be made thicker for the same weight. Stiffness of the sandwich increases with the cube (third power) of the thickness of the sandwich.

There is a reason why e.g. most composite aircraft are built with foam cores or honeycombs (because that's where weight really matters).

In principle I have to agree with brainfart, strength to weight a foam core wins every time, however without knowing firstly what the monocoque is for and secondly what and where other bits need attaching it is almost impossible to say. It is fairly easy to build a very strong, stiff and lightweight structure, attaching other pieces of hardware and transferring loads successfully is a totally different matter. More information please. 

Warren

Carbon Copies Ltd

> Stiffness of the sandwich increases with the cube (third power) of the thickness of the sandwich.

This means doubling core thickness results in 8 times the stiffness. At least in theory.

Thanks for all your help