It is easy to find on Google that the tensile strength of graphene is 130,000 MPa. But what is it's compressive strength?
Graphene is an allotrope of carbon (same as diamond, graphite and fullerenes ), (allotrope to my mind is a fancy way of saying that the molecules can be arranged in different configurations). Graphene in particular arranges the molecules of carbon in a two dimensional hexagonal lattice.
Figure: hehagonal lattice of carbon (source Graphene-info)
In essence it looks like very thin surface, very much like a thin sheet of paper, with a dimension of 1-2 [nm] (or 1-2 millionth of a mm). Therefore, it has a similar behavior to a piece of paper. I.e.
- the tensile force required for failure for a sheet of paper is well defined.
- the compressive force required to fail (through crumbling) varies depending on the dimensions and the support. I.e. buckling becomes the dominant method.
I.e. a longer sheet would fail under its own weight.
For comparison purposes, Diamond, has the following lattice. The lattice is face-centered cubic Bravais lattice
Figure: Diamond lattice(source uiuc.edu)
The three dimensional nature of this structure allows the creation of 3d objects (with varying thicknesses).
A fiber as thin as a few atoms doesn't have a comprehensive strength by itself. it will buckle or break and crash into tiny microscopic particles that are dangerous if breathed by the workers.
it depends on how it is embeded in resin and what is the compressive strength of the resin.
also because of the density of the composite material which is usually low the compresive strength i lower significantly.