SYSTEMS AND METHODS FOR ANALYZING FLUTTER TEST DATA USING DAMPED SINE CURVE FITTING WITH THE CLOSED FORM SHAPE FIT

System identification from free response time decay history data of a dynamic system employs a new closed form shape fit for solving the dynamic system free response decay equation. The closed form shape fit allows for the treatment of the mode shapes as linear coefficients and allows the mode shapes for each sensor to be computed independently, thereby reducing computation time. The closed form shape fit efficiently provides mode shapes for a large set of sensors based on a fit from a small set of sensors. The closed form shape fit combined with a non-linear fit of frequency and damping characteristics efficiently estimates the optimal solution, thereby reducing the time to completion of non-linear optimization. A nonlinear optimization can incorporate the closed form shape fit into determining the Jacobian matrix of sensitivities and evaluating the residuals, thereby reducing the number of parameters and reducing the time to completion of the non-linear optimization.