STRESS ANALYSIS OF THIN ELASTOPLASTIC SHELLS

A stress analysis is presented of thin shells, having large deflections and being loaded into the strain-hardening range. Plastic strain incompressibility is assumed. The two governing differential equations in terms of the stress function and the normal displacement are presented in two alternate forms. In the first form corresponding equations of the elastic problem are modified only by adding the integrals of the plastic strains. The alternate form requires that the coefficients of the differential equation operators become dependent on the load, and an iterative process is presented by which the solution can be obtained, starting from the known elastic solution. Utilizing the first form, the analysis is applied to the problem of stress concentration around a circular opening, with and without a reinforced ring in a pressurized spherical shell. Numerical solution is obtained by an iterative procedure, using the finite difference technique for the special case of linearized displacements and deformation theory of plasticity. The speed of convergence decreases with increase in pressure and decrease of strain-hardening coefficient. The procedure required to apply the incremental theory and to include finite displacements is also discussed in detail.

• Corporate Authors:

  Naval Ship Research and Development Center

  Bethesda, MD  United States  20034
• Authors:
  • Lomacky, Oles
• Publication Date: 1970-5

Media Info

• Pagination: 111 p.

Subject/Index Terms

• TRT Terms: Elasticity (Mechanics); Plasticity; Shells (Structural forms); Stresses; Structural analysis
• Uncontrolled Terms: Stress concentration
• Old TRIS Terms: Shell theory
• Subject Areas: Marine Transportation; Materials;

Filing Info

• Accession Number: 00015120
• Record Type: Publication
• Source Agency: Defense Documentation Center
• Report/Paper Numbers: NSRDC-3295
• Files: TRIS
• Created Date: May 13 2003 12:00AM