Stability and optimization of viscoelastic cylindrical shells made out of composites under combined loading

Abstract

The numerical investigation of the functions describing the physical restrictions in the problem of the optimization of cylindrical shells made out of composites with a viscoelastic binder which has been carried out in this work has shown that the optimization problem which has been considered above belongs to the class of convex programming problems. The parameters of the optimal design for the shell, i.e., the mass G* and the relative fractions of the reinforcements Θ1, Θ2, and Θ3, arranged according to the corresponding schemes, are substantially dependent on the time for which the construction is utilized τop. A comparison of the optimal designs of a shell at the same utilization times τop has shown that the use of three-dimensional reinforcement schemes with an insignificant gain in mass provides a gain in the volume of the reinforcement in comparison with the planar reinforcement schemes of 22 to 24%. In the optimal shell designs, the increase in the flexure with respect to time is always a nondecaying nature.