Flutter of composite laminated beam plates with delamination

The flutter characteristics of two-dimension al delaminated composite panels at high supersonic Mach numbers are investigated theoretically. Classical small deflection laminated plate theory and quasisteady, supersonic aerodynamic theory are employed. A simple beam-plate theory model is developed to predict the flutter boundaries of delaminated composite two-dimensional beam plates with simply supported ends. The effects of delamination position and size on the flutter boundary of plate with different fiber orientation and stacking sequency are studied in detail. The results reveal that the presence of a delamination degrades the stiffness and the natural frequencies of the plate and thereby decreases the flutter boundary of the plate. However, for certain geometries, the flutter boundaries were raised due to the flutter coalescence modes of the plate altered by the presence of a delamination in the plate. The restriction in the two-dimensional beam-plate model is to evaluate the effects of delamination on the flutter boundary for a two-dimensiona l plate only. But the trends of the effects of delamination on composite panel flutter can be evaluated for comparison purpose using this theory.