.. _V2.01.320: **v2.01.320** SDLD320 - Transient response of a free system of 3 masses and 2 springs under harmonic excitation =================================================================================================================== **Summary:** We consider the transient analysis of a discrete linear mass/spring system with three completely free degrees of freedom. This system has non-proportional damping. Sinusoidal excitation is applied to one end of the system. In this problem, we test, through a discrete model, the calculation of the transient response of a system whose rigid modes are not fixed. We are only interested in the transitional regime. To do this, the solution will be sought through integration on a complete modal basis. The results obtained (displacement, speed and acceleration) are compared to an average of results from industrial codes and an improved :math:`\beta` -Newmark numerical integration method. .. toctree:: :hidden: self .. toctree:: :maxdepth: 2 :numbered: Probl_me_de_r_f_rence Solution_de_r_f_rence Mod_lisation_A Synth_se_des_r_sultats