The junction between cylindrical part and end dome is the most critical place of the filament wound composite pressure vessels because the shear forces and bending moments occur in this area. The strength analyses of junction between cylindrical part and different types of known end domes based on influence coefficients method were performed for filament wound composite pressure vessels manufactured using glass-epoxy and carbon-epoxy composites. Four known end domes were considered that is, a spherical shell, a geodesic-isotensoid shell, a shell based on minimizing of the Tsai-Hill’s strength criterion and shell designed in authors’ previous work (Hoffman 1 shell). Moreover, the study is also dealing with design of optimal end dome shape which takes account to the junction area. Finding of optimal end dome shape was based on data-driven evolutionary algorithms. Using input dataset from the analytical simulation surrogate models were created using Evolutionary Deep Neural Nets (EvoDN2) algorithm. The multicriterial optimization procedure was performed using Constrained Reference Vector Algorithm (cRVEA) optimization algorithm. Results indicates that the optimal end dome shape highly depend on material properties.

The paper describes analytical and numerical solutions for five selected domes (a spherical shell, a geodesicisotensoid shell, a shell with zero transversal strain, a shell with zero transversal stress, and a shell with identical strain) for composite pressure vessels manufactured by means of filament (helical) winding. The stresses and strains in the domes were evaluated analytically from known equations with the use of MATLAB script for numerical evaluation and via finite element analysis (FEA) with Abaqus software and results were compared with each other. Two failure criteria, interactive and non-interactive, were chosen for the evaluation of critical areas of the shells. Moreover, the best dome shape for a given material and polar hole/equator ratio was selected for various types of failure, i.e., a loss of tightness/leakage or the failure of the fibers.