Flutter and divergence instability of nonconservative beams and plates

For a conservative system, the only possible instability is of divergence type. For a nonconservativesy stem,h owever,i nstabilityc an be of divergencef,l uttero r both, dependingo n the amount of nonconservativenesIsn. this paper, we study the instabilityo f a cantileveredb eam and a simplys upportedp late,s ubjectedto a combinationo f fixeda nd followerf orces.A nonconservative parameteri s introducedt o providea llp ossiblec ombinationso f thesef orces.F or the beam,i nstability changesf rom divergenceto fluttera t a criticalv alueo f this parameter.F or valueso f the parameter above the criticalv alue,t he flutter instabilityr emainsa s the only instabilityp attern, in contrast to implications in the literature. For the plate, the instability is governed by flutter for a certain range of the nonconservative parameter, even though divergence instability still exists. The range depends on the geometry (aspect ratio) and material property (Poisson’s ratio) of the plate.