Analysis of dynamic stability for composite laminated cylindrical shells with delaminations

By introducing the Heaviside step function into the assumed displacement components and using the Rayleigh–Ritz method for minimizing the total potential energy, a set of dynamic governing equations for the delaminated cylindrical shells is derived. Then, the dynamic governing equations are written as the Mathieu-type equations to describe the parametric vibrating behavior of the shells, and these equations are solved by employing the Bolotin method. The numerical results for the dynamic stability of laminated cylindrical shells with delaminations are presented. The effects of the amplitude of external excitation, the delamination size and location and the material properties on the natural frequency and the principal dynamic instability region of the delaminated cylindrical shells are discussed. Present results are compared with available data.