Bullets at terminal velocity actually do very little damage - as do birds at terminal velocity.
In the case of bullets, they leave the gun at a speed much greater than their terminal velocity, and once outside the barrel immediately start slowing. Only if shot, more or less, exactly straight up in the air do they ever actually slow to terminal velocity before impact. As someone else mentioned, Mythbusters demonstrated this in an episode.
Regarding birds and aircraft... again we are talking about speeds greater than the terminal velocity of either the birds or planes - only achieved via the jet engines on the plane.
What you're talking - while correct from a technical standpoint - completely neglects the concept of terminal velocity, and as such incorrectly implies (or at least appears to imply) that there is substance to the concern.
I would submit that the terminal velocity of the truss will be quite low, and in combination with the low mass incapable of doing any significant damage to anything.