Author(s)

H. Martikka & E.Taitokari

Abstract

The main purpose of this study is to present results of designing optimally flat ends of large industrial large vessels of fiber reinforced plastic using failure criteria analysis. It is known that in the case of pressure vessels flat ends are more advantageous than domed ends due to smaller space requirements. The concomitant disadvantage of higher stresses can overcome by using a novel idea of concentric hollow shells laminated together to form a light might and stiff shellwhichisalsooptimallycost-effectivetomanufacture.Conventionally sandwich flat ends are made using a hard porous core material. The goals and constraints are both formulated as fuzzy satisfaction distribution functions. The design variables are discretized as choices of geometrical and material vriab1es. Loads are applied as given parameters. The final design is obtained as a balanced trade-off solution giving optimal performance. Then FEM models for the final design are used to check the model and the 3D Hill failure criterion is used to find out critical locations close to the shape discontinuities. The results of application of basic theory and FEM are compared. This information is used to optimse the structure to satisfy the needs of end user customer and also the manufacturer. .

Keywords