Abstract: Recently the author proposed a new In-Operation modal identification algorithm, namely the Stochastic Modal Appropriation algorithm (SMA) which identifies the frequency and the damping ratio simultaneously in a single step. The key idea is to rotate parametrically the outputs correlation sequence so as it looks like the system impulse response.

We show in this work that SMA rejects automatically harmonics as well as spurious/numerical modes leading therefore to physical-only modes identification. After a mathematical proof, the method is validated on a simulated example.