4 degrees of freedom Analytical results 1 Compaction 1 Degrees of freedom (mechanics) 1 Electric motors 1 Granular materials 1 Input power 1 Non-ideal excitation 1 Nonideal excitation 1 Numerical results 1 Quasi-static 1 Sommerfeld effect 1 System state 1 Torque curves 1 Vibro-compaction 1 Vibrocompaction 1