My supplier has something called kevlar honeycomb, as far as I know it is made out of kevlar paper(?) pre-impregnated with phenol resin. It is realyyyy expensive 70euro exl.vat for 2mm x 2550mmx1250mm and 48kg/m^2, he claims that it is the lightest sandwich in the world. I don't have money to buy it, but when I have some $ I will make some reviev of that, this is how it looks like :

Florin, it all depends on your specific application.  Such severe shear loading would probably not be typical of many common uses of a cored panel.

Dravis, did you do quite a lot of tests on your composite panels??? 75kg/cm2  is quite impressive amount of load. 

I did a crude test of a couple of cored panels for a personal project of mine.  Being insane, i prefer to run things over with cars!!

This is my test panel using 25mm aluminium honeycomb 3.2mm cell and 2mm carbon skins:



and a 10mm foam cored panel with 1mm skins:

Albeit under a normal car!!!   I will be destroying said test panel under my 4x4 later in the week!


Although crude tests (and that was the point for me really), it demonstrates how composite panels can be very strong for certain applications and that a cored panel is a great way of doing that.

The particular reason for those tests was to help determine a initial design laminate for a carbon chassis.  Typical steel car monocoque body shells will likely have steel no thicker than 3mm in structural areas and certainly thinner on a lot of the floor pan areas and such similar steel panels will buckle with ease with a fraction of the load used above.

Sure its broadbrush rough engineering but it proves the point i set out and gives me a base laminate profile i can use in the CAD drawings and simulations and work from there.

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant