There are many things you can do... But I would immobilize the wires right at the point where they connect to the screw terminals with tie wraps or plastic wire clamps and make SURE that the wire ends are tightly twisted before clamping them in the screw terminal blocks. Crimping Ferrules are a good choice as long as you have the "Proper" crimper... Pliers won't really do the job and then you are back to loose ends. Soldering and solid wires are OUT for the same reason, Both are solid and although it takes longer in a higher vibration environment both methods will fail and break. There is also a "preferred" wire, one with many small wires. Many of the jumpers purchased form Asia work well with repeated use... for 2 reasons, 1. The wire may have 15 or 20 strandds and 2. there is a strain relief at the shell or molding on the end of the wire. Many small strands will work for RS485 Very well and are more difficult to fray and break because of their size and number smoe might break, those are more likely to be ones nicked in stripping and in the end... (no pun intended) prevention of this condition depends strongly on tools and technique... In My Direct Experience.
Doc