Minimum weight of internally pressurised domes subject to plastic load failure

A series of eight mild steel domes subjected to internal pressure were tested up to burst in order to verify optimal solutions obtained by a zero order optimisation subroutine and a str ess analysis code. Four classes of minimum weight domes were obtained. The first one was sought within tori-spherical shells of constant wall thickness. The second case cot responded to a variable meridional profile described by a generalised ellipse and a given wall thickness. in the third case, the uniform wall thickness became an additional design variable. In the forth case both the meridional shape and variable wall thickness along the meridian were used as design variables. The plastic load was greater than 20 MPa in all four cases. The weight I eduction obtained for the above mentioned four cases was 18, 19, 27 and 31%, respectively. Comparison with the fully, stressed design is also provided. (C) 1997 Elsevier Science Ltd.