Nonlinear vibration of corrugated-honeycomb cylindrical shells in thermal environments

To balance the weight-saving and mechanical compensation features of lightweight engineering structures, fresh composite sandwich cylindrical shells with three-phase hybrid composite skins and a corrugated core filled with hexagonal honeycombs are designed. A matched dynamic model is first proposed to disclose the nonlinear vibration behaviors, including the nonlinear frequency, the amplitude-frequency attribute, and the phase plane manifestation during primary, sub-harmonic, and super-harmonic resonance occurrences, while the thermal effect is taken into account. The equivalent stiffness parameters of the core are derived using the strain energy invariance principle at macro and micro scales, and the variable material properties of the three-phase hybrid composite skins incorporating material-filled defects are characterized through the Halpin-Tsai technique and mixture law. The first-order shear deformation theory merging geometric large deformations and the Euler-Lagrange equation is adopted to integrate the modeling framework, in which the thermal expansions induced by temperature climbs are given via Green-Lagrange nonlinear strains, and the static condensation and time-domain multiscale methods achieve nonlinear vibration solutions. After the model is proven to work, the nonlinear frequency and various harmonic resonance behaviors are characterized under different configuration schemes and heat impacts, with the influence mechanisms being elucidated. Some actionable guidelines for improving the dynamic capabilities of the structure are provided.