Flutter characteristic of composite laminates with lamination parameters

Composite laminate modeling based on lamination parameters is fulfilled and the parameter input problem of lamination parameters with Natran is solved, using a simple numerical example to demonstrate its validity. With composite laminate modeling method based on lamination parameters and p-k method for calculation of flutter and divergence speeds, flutter and divergence characteristics of a cantilevered laminate are studied using lamination parameters. The effects of principal-axis stiffness and bending-torsional coupling on the flutter speed are emphasized The results show that compared with the bending stiffness, change of torsional stiffness has a more obvious influence on flutter speed. And the flutter speed decreases with decrease of torsional stiffness. The switch of flutter mode may occur due to change of stiffness, which leads to interrupt change of flutter speed and discontinuity of flutter speed contours in lamination parameter plane. With constant normalized stiffness matrix, the flutter and divergence speeds can be improved and have a linearity relationship with the laminate thickness.