Two-Dimensional Coupled Flutter Method Based on Genetic Hybrid Algorithm

Based on the traditional systematic analysis method of 2d2DOF (two dimensional two degree of freedom), flutter analysis was transformed into a solution to the nonlinear equations of system vibration frequency, innovatively. Several numerical iterative methods for superlinear convergence, such as the quasi-Newton method, were introduced on the basis of numerical analysis theory. Then, the local convergence and initial value dependency of these methods in numerical iteration were studied. To avoid the above-mentioned risks in the flutter analysis, the genetic hybrid algorithm, which has advantages in global searching, was combined with the optimal algorithm "L-M" for local convergence correction, and introduced into the 2d2DOF flutter analysis; a new analysis method was subsequently proposed. The sample numerical analysis showed that in each detected wind node, the calculation errors of the system vibration circle frequency and the system-implicated damping ratio under the two methods were lower than 0.1 per thousand, and the results were almost the same. Thus, the new method is effective, and the corresponding calculation result of the critical wind velocity is consistent with the traditional method; this shows that the new calculation procedure is feasible and the calculation results are accurate. Compared with the traditional method, the proposed method has the advantages of unconditional convergence, wherein initial values do not require artificial selection in each step of the solving process.