Summary of results ====================== The results are satisfactory. The relative error corresponds to the numerical error associated with the integration of time. The initial conditions are well taken into account. It is concluded that *Code_Aster* correctly simulates a release in linear dynamics. This test is also a functional validation of the recovery in the form of a function of the evolution over time of the participation of a mode, as well as a validation, in the case of a linear relationship, of the RELA_EFFO_VITE feature.