I would not use Explicit Dynamics, I would use Static Structural.

I would not use an Explicit Dynamics material. Those have equations that are useful for tracking very high strain rates that occur during explosions or high speed impact events.

Tensile testing is done to acquire input data for simulation models.

Why are you building a simulation of a tensile test? What do you want to see? In Explicit Dynamics, you see the part fracture into two pieces.  You won’t see that in Static Structural. Instead you will see the stress and strain at the point when the fracture would have occurred.