Accession Number : AD0709446

Title :   STRESS ANALYSIS OF THIN ELASTOPLASTIC SHELLS.

Descriptive Note : Final rept.,

Corporate Author : NAVAL SHIP RESEARCH AND DEVELOPMENT CENTER WASHINGTON D C

Personal Author(s) : Lomacky,Oles

Report Date : MAY 1970

Pagination or Media Count : 111

Abstract : 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. (Author)

Descriptors :   (*PRESSURE VESSELS, SHELLS(STRUCTURAL FORMS)), (*SHELLS(STRUCTURAL FORMS), STRESSES), PLASTIC PROPERTIES, STRAIN(MECHANICS), SHEAR STRESSES, DEFORMATION, DIFFERENTIAL EQUATIONS, NUMERICAL ANALYSIS, SUBMARINE HULLS

Subject Categories : Containers and Packaging
      Structural Engineering and Building Technology
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE