Flutter monitoring with the statistical subspace method for the 2-D structure

The flutter is a dangerous phenomenon that occurs in aeronautical structure as well as the longscale building and bridge. Detect and prevent flutter to happen in mechanical structures under natural or controlled excitation has been a subject of interest within the engineering community. In the proposed approach, a three-degrees-offreedom cantilever wing MW-2 is modeled using a linear discretization of the (M,C,K) continuous equation, which depends on the structural properties as well as the airspeed. A simulator is developed with this model to output time series at different airspeeds so that a progressive evolution to flutter can be illustrated. Making use of output-only, a covariance driven subspace identification method is employed to assess the stability of structures through classical parameters such as frequencies and damping, then with the flutter margin indicator which measures an interaction between two modes. Then, a statistical subspace-based residual test for monitoring the discrete flutter margin is applied on the simulated data to detect the flutter onset and results are reported.