I apply a velocity on one end of nanowire with another end fixed.
I creat a group including the middle section of the nanowire.
During the process, I dump the stress (the group created) and
I find some stress is positive, while the other is negative.
I am puzzled by this. I have thought all the stress should come out with
the same sign under this load.
Is there some possible reason for this?
State Key Laboratory of Nonlinear Mechanics (LNM)
Institute of Mechanics, Chinese Academy of Sciences
No.15 Beisihuanxi Road
Beijing 100080, P. R. China