Tensile test under LS-DYNA

Dear all,

I would like to run a tensile test under ls-dyna of a mild steel  and
apply a 7000 N load to the dog bone specimen on a explicite scheme.

Unfortunately, I
have wild deformations ( and an error) on the nodes on edges where the
load is applied, so can you please tell me what are the importants
constants (like time termination, mass scale,...) and how to perform a
perfect run?

Have a good day,

Thank you

M.