allan wrote:... i was wondering why don't F1 teams use some kind of a metal such as aluminium ,for example, to construct their cars' floors ... Since the floor is the lowest part of the car, they can put most of the weight in that area, which would allow them to lower the center of gravity ...
Well, of course, in a
sense they
do construct the floor of aluminium. But its density alone would speak against the use of it as ballast. It's a component in the carbon fiber sandwich composite of which parts of the chassis are constructed. The aluminium therein is a honeycomb structure that evidently can be processed into complex shapes (a process the finer niceties of which are unfamiliar to me). I've had the chance to examine such parts rather superficially, but there weren't enough indications for me to draw any definite conclusions. I do know the process by which a planar mesh is produced. Aluminium deforms irreversibly under mechanical stress, but I don't know whether it's that or if the honeycomb sheet is machined down to curving shapes without altering all the dimensions of the mesh to produce complex shapes. In either case the structural calculations down to a certain accuracy can't be very easy.
What I do know is that the honeycomb has one of the best strength to weight ratios of available materials. Sandwiched with carbon fiber, the best properties of both materials can be utilized. Whereas a solid aluminium part is susceptible to advancing stress fractures and such and the shapes would have to be designed by avoiding specific physical discontinuities in forms, composites may offer more freedom of design by avoiding such problems by default. Anyway, reading this forum it's become clear to me (even if I wasn't under any illusion before, either) that I'm a complete dilettante when it comes to truly understanding how forging, different kinds of stress, chemical reactions, heat and purposeful deformations alter the structural properties of metals and alloys. And that it's likely I will remain so indefinitely. It's one thing to look up figures from charts, quite another to understand the goings-on inside the material at any depth.
Fortunately we've got people around who can easily satisfy our curiosity to the degree that we're able stretch our imaginations to ask such things. There are some very flexible CAE programs around that do take into account the effects of deformations in the production of the parts on the materials used. Perhaps someone here could delve a little deeper into working with aluminium mesh in 3D and the processes of bonding it with carbon fiber?
) as it is an aerodynamic surface and is presumaby subject to quite a deal of force pulling it down.