Here is an example patent:
Lightning strike protection method and apparatus - Patent # 7525785 - PatentGenius
One thing immediately evident here is the mistaken notion that simply conducting the current through the composite is sufficient to protect it. Again, the main thing that protects an aluminum airframe is the fact that conduction currents MUST occur on the OUTER SURFACE of a metal conductor - the electric field cannot penetrate more than a few thousandths of an inch into metal because the internal free electrons rearrange themselves to cancel out the applied field - thus a conduction current can only exist very near the surface of any metal. However, if this metal is itself encased in some other material - for example, an insulated wire - that material can still become extremely hot from the kinetic action of the conduction electrons. No matter what ground testing has been performed, I very much doubt that an embedded metal mesh could deal with the megaJoules of current coming from a large lightning strike without blasting away the surrounding matrix in which it is embedded. Such a mesh would necessarily have to exist on the outer surface of the composite to be really effective. The only realistic test of such things is to fly around in a thunderstorm with a drone, and try to have it take a strike, and look at the results. Has anything like this been done?
-drl