OPTIMUM DESIGN OF RING STIFFENED CYLINDRICAL SHELLS

This report deals with the optimum structural design of circular cylindrical shells reinforced with identical uniformly spaced T-ring stiffeners, and subjected to external pressure loading. The optimization problems considered are of three types: (1) minimum-weight designs, (2) design for maximum separation of the lowest two natural frequencies, and (3) design for maximum separation of the lowest two natural frequencies which have primarily axial content. Gross buckling is precluded by specifying a minimum natural frequency, and additional behavioral constraints preclude yielding or buckling of panels, T-ring stiffeners, and web and flange instabilities within each T-ring. Analysis is based on use of an equivalent orthotropic shell model, and optimization is accomplished through use of a sequential unconstrained minimization technique. Examples indicate that a small increase in weight above optimum (minimum) values can result in relatively large increases in frequency separation, and that maximum frequency separation is obtained when second and third lowest frequencies approach each other.

• Corporate Authors:

  University of California, Los Angeles

  Department of Mechanics and Structures
  Los Angeles, CA  United States  90024
• Authors:
  • Bronowicki, A J
  • Nelson, R B
  • Felton, L P
  • Schmit, J R
• Publication Date: 1974-2

Media Info

• Features: References;
• Pagination: 25 p.

Subject/Index Terms

• TRT Terms: Cylinders (Geometry); Mechanical rings; Orthotropic plates; Shells (Structural forms)
• Uncontrolled Terms: Cylindrical shells
• Old TRIS Terms: Orthotropic plate theory; Stiffened cylinders; Stiffening rings
• Subject Areas: Marine Transportation; Materials;

Filing Info

• Accession Number: 00054149
• Record Type: Publication
• Source Agency: Ship Structure Committee
• Report/Paper Numbers: UCLA-ENG-7414
• Contract Numbers: N00014-69A-0200-4048
• Files: TRIS
• Created Date: May 7 1974 12:00AM