Summary: The paper investigates the benefits that the SMA-behaviour can introduce in the dynamical response of a structural system. The influence of SMA tendons contributing to the overall strength of a simple elastic‒plastic structural model undergoing horizontal shaking and subject to vertical loads is firstly analysed, proving that coupling super-elastic members with elastic‒plastic structures yields an excellent performance in attenuation both of the $P-{\varDelta}$ effect and of the final residual deformation. In the second investigation, this system is looked at as an isolation device and is introduced in a m.d.o.f. elastic‒plastic structural model; its attitude in suppressing plastic deformations in the super-structure is demonstrated.