Refined model of thermoelastic-plastic dynamic deformation of flexible reinforced cylindrical shells

Within the refined theory of bending, a coupled initial-boundary value problem of thermoelastic-plastic deformation of flexible circular cylindrical shells with arbitrary reinforcement structures is formulated. The tangential displacements of the shell points and the temperature along the thickness of the structures are approximated by high-order polynomials. This makes it possible to take into account, with varying degrees of accuracy, the weak resistance of fibrous sheaths to transverse shear and to calculate wave processes in them. From the obtained two-dimensional equations of the refined theory, in the first approximation, the relations of the traditional non-classical Ambartsumian theory are obtained. The geometric nonlinearity is modeled in the Karman approximation. The inelastic deformation of the components of the composition is described by the relations of the theory of flow with isotropic hardening. In this case, the loading functions of the materials of the composition phases depend not only on the strengthening parameter, but also on the temperature. For the numerical solution of the formulated nonlinear coupled two-dimensional thermomechanical problem, an explicit scheme of time steps is used. We studied the axisymmetric elastic-plastic deformation of flexible long cylindrical shells, which are reinforced in the circumferential and axial directions. Fiberglass and metal-composite structures from the inner front surface are loaded with pressure, which corresponds to the action of an air blast wave. It is shown that for an adequate calculation of temperature fields in the structures under consideration, it is advisable to approximate the temperature over their thickness with a 7th order polynomial. It has been demonstrated that at some points fiberglass shells can additionally heat up for a short time by only 10…11 °C, so the thermal response can be disregarded in their calculations. Metal-composite structures can additionally heat up by more than 40 °C. However, for their calculation it is also possible to use the model of elastoplastic deformation of the materials of the composition components. It is shown that when studying the dynamic inelastic behavior of both fiberglass and metal-composite cylindrical shells, it is advisable to use the refined theory of their bending, rather than its simplest version, the Ambartsumian theory.