DAMPING VIBRATION AND INTERLAMINAR STRESSES STUDY USING MIXED LAYERWISE THEORIES FOR VISCOELASTIC LAMINATED CYLINDRICAL SHELLS

By use of the mixed layerwise theories and the interpolation functions of displacements and transverse stress, the dynamic equations of viscoelastic laminated cylindrical shells were derived. The predicted vibration frequency and loss factor show the good agreement with the Okazaki A’ experimental results for the two-layer cylindrical shells. The amplitudes of interlaminar transverse stresses were computed for different Young’s modulus and thickness of viscoelastic layer. The results show that very high interlaminar transverse normal stresses are the main factor resulting in delamination for the free-damped laminated shells and that using a circular-reinforced viscoelastic layer will effectively decrease the amplitude of transverse normal stress.