Dynamics of Sandwich Cylindrical Shells with Inhomogeneous Core Under Operational Loads

The effect of distributed end-face and local axisymmetric operational non-stationary loads on sandwich cylindrical shell elements of rocket bodies has been studied. The action of the engine is characterized by longitudinal forces that have time-varying frequency and amplitude and are applied to the end of the shell. Additionally, we have simulated local axisymmetric external impulsive loads applied along the directrix of the cylindrical shell to the place of ribs and between them to imitate an explosion of an elongated cumulative instantaneous charge. Given the different material properties of the face layers, light core, and reinforcing ribs, it is advisable to employ the finite-element method. By finite-element modeling of the dynamics of the structure under operational loads, this research enables thoroughly investigating the effect of the light core and facilitates choosing the optimal locations for applying local axisymmetric impulsive loads. The numerical results obtained from real object simulations, based on the developed methodology, allow us to give recommendations for determining the optimal amount of cumulative charge necessary for separating the rocket’s spent stage while maintaining its prescribed trajectory.