Deformation of asymmetrically loaded, symmetrically prestressed orthotropic shells of revolution.

Proceedings of a Conference on Computer Oriented Analysis of Shell Structures Held at Palo Alto, California on 10-14 August 1971

“…The results are not unlike thost of Fig. 8 for the other Imperfection shape (39) except that for very small imperfection amplitudes the bifurcation mode imperfection (39) causes larger relative reductions. Fig.…”

“…These analyses make use of four basic element types ( Figure 5): 1) conical and meridionally curved axisymmetric shell elements [25][26][27][28][29][30]; 2) triangular or quadrilateral flat and curved elements [21][22][23][31][32][33][34][35][36][37]; 3) axisymmetric solid of revolution elements [38][39][40]; and 4) three-dimensional solid elements [41]. In addition, stiffened shell structures use straight and curved beam elements to represent stringers and frames.…”

“…Even so, there does not appear to be an% ineral curved triangular or quadrilateral element which completely satisfies all convergence and rigid body conditions. Two-and three-dimensional solids are tre3ted using either the axisymmetric triangular ring element or the general solid element (e.g., a tetrahedron) [38][39][40][41].…”

“…The resulý8 are not unlike those of 7ig. 8 ior the other imperfection shape (39) except that for Very small Imperfection amplitudes the bifurcation mode imperfection (39) caus2s larger relative reductions, Fig. 9 is a plot of the elastic buckling pressure (i.e., calculated with a -0) in the presence of the suam flat spot imperfections.…”

“…Then this design becomes a starting design for iteration using equation (39). This two stage; approach has a better chance of converging to an absolute minimum when there are stress and displacement constraints.…”