Sampat Kumar
Ansys Employee

Hi Fatah,
Increasing the density is an option to decrease the simulation time, but it is more related to the mass scaling and CFL time than reducing the simulation time. There is a recommendation that you can increase the density by around 5% for dynamic analysis, and most importantly, it should not change the physics of the problem.
Explicit solutions do not perform equilibrium iterations to enforce a force balance in the system; explicit solutions rely on energy balance in the system.
If you increase the mass, then the kinetic energy also increases.
Kindly follow the link to know more about the mas scalingĀ

Is it possible to reduce the simulation time? Please let me know.