I have done this with Nanotubes in my electroinc  structure code FreeON

I do not know lamps, but the  strain relation can be computed in any code that gives a toto energy. For periodic systems I just increase and decreased the box size and computed the single point energy, fitted it and took the derivative to get the force(divide by l0 to get force per length). Tested with different length nanotubes. If the gold rod is periodic in x this is what I suggest you do 

For a none periodic rod its a little trickier. I suggest you fix, if lamps lets you, the face atoms and just increase the separation. you can either extract out the force on these atoms, sum up the x component to get the plying force, ore compute the total energy, fir and compute the derivative

I am not aware of computer program for this. But one can measure the displacements on screen of a FEG SEM or a TEM online by using a nano-scale marker.

Thanks a lot for reply!

I found another way to calculate strain and displacement vector, by using OVITO http://www.ovito.org/.