Frame material in F1, Carbon Fibre or Titanium?

[riff_raff]

With adhesively bonded joints between metals and carbon composite laminates, the CTE mismatch and MoE mismatch can also be an issue. If you have an adhesive joint between an aluminum insert and a carbon composite part that is subject to bending, the large difference in material stiffness between the aluminum and carbon can result in shear failure at the bond line, unless the relative section thicknesses are tapered appropriately along the bond line.

[flyboy2160]

With adhesively bonded joints between metals and carbon composite laminates, the CTE mismatch and MoE mismatch can also be an issue. If you have an adhesive joint between an aluminum insert and a carbon composite part that is subject to bending, the large difference in material stiffness between the aluminum and carbon can result in shear failure at the bond line, unless the relative section thicknesses are tapered appropriately along the bond line.

this is the correct - and very expensive- way to transition the load in a highly stressed metal-to-composite joint.

but even F1 may draw the line when the tapering would be too complex:
http://www.f1technical.net/forum/viewto ... rm#p295751

[edit] here's a sketch of the type of stepped lap joint riff raf and i are talking about. it's very time consuming to get the composite plies trimmed and to sit down in those steps in the metal part. i'll try to find a picture of a real one, but they are frequently proprietary.

[riff_raff]

The real trick is to get the end thickness of the metal part wafer thin. If you can machine the end thickness of the metal part to gradually taper along its length to something like 0.5mm, it won't have enough radial/bending stiffness at its edge to initiate a peel failure in the bond line.