ITERATIVE REAL COMPLEX EIGEN-SOLVER AND PARALLEL-PROCESSING FOR NONLINEAR PANEL FLUTTER ANALYSIS

In the frequency domain analysis of the limit cycle motion of a flutte ring panel, the operation of a nonlinear eigen-solution is computation ally costly. Nonlinear panel flutter analysis includes repeatedly usin g real and complex eigen-solutions in iterations and in the searching of the stable limit cycle motion. This study presents an efficient ite rative real and complex nonlinear eigen-solver to greatly speed up the solution procedure. This new nonlinear eigen-solution adopted a power iteration-scheme and has the following features: (1) it avoids repeat edly using a costly eigen-solver, (2) it is not sensitive to the initi al iteration vector, (3) it operates in the real region for a complex solution, and (4) it solves for the single nonlinear mode deflection d irectly. Those features are particularly suitable for nonlinear panel flutter analysis in which the limit cycle motion is a stable vibration , the eigenvalue and eigenvector are amplitude related and only the do minant eigenvector has a practical meaning. The parallel computation i s designed to speed up the searching of the stability of the limit cyc le motion. The parallel computation was performed by using PVM (Parall el Virtual Machine) on IBM RS/6000 workstations.