Rational reinforcing structure of thick-walled cylindrical shells operating in regime of vibrations or static stability under external pressure

Abstract

1. Calculations for a three-layered cylindrical shell with R/h = 10 showed that for all the examined criteria of quality of the design the greatest effectiveness of the design is attained in the case of a “hybrid” stack whose inner and outer layers are reinforced circumferentially, the middle layer (h 2 * ≊ 0.4 h) is a dispersely reinforced composite. 2. In comparison with the best shell designs with plane reinforcement of the layers, such a “hybridization” of the stack makes it possible to increase the indicators of effectiveness additionally by 8.8 to 16.5% in dependence on the state of stress and strain of the shell. 3. The results of a comparison of the calculations carried out with four different kinematic shell models are in agreement with the conclusions of [7] as regards the possibility of using the simplest kinematic homogeneous models in engineering calculations of stability and vibrations; however, these models take transverse shear and compression of the normal of a thick-walled laminated structure into account.