1. Reference problem#
1.1. Geometry#
The following system is considered:

1.2. Material properties#
The characteristics of the system are:
\({k}_{1}={k}_{2}=1N/m\)
\({m}_{1}={m}_{2}=1\mathit{kg}\)
\(e=1m\)
\(K=30N/m\)
1.3. Boundary conditions and loads#
The left edge of the system is fixed and the masses move along the axis of the springs.
1.4. Initial conditions#
We try to follow the evolution of the periodic solution from the second mode of the underlying linear system (contactless system).