Two metalical piece of al and cu standing opposite of one another around the x axial. al rotates around x circle and cu approches to al with minimum axial force of x . while al is approching it is expected that on the impact of the friction between al and x tempreature goes up and defussion occures but while it undergoes under cu condition can not keeps its structure and brokes up . What is ths reasen of cu broking up? I have attached additional information. I would appreciate it if you could please help me.
If the stresses generated in the simulation are sufficiently large, it is natural for the solid structures to undergo fragmentation. You can reduce the stresses by lowering the speed of rotation (maybe even setting it to zero initially), and also reducing the force used to push the Cu structure against the Al structure. More generally, you should first test your ability to model the mechanical properties of Cu and Al by reproducing published results on MD simulations of shear deformation using the same interatomic potentials.