ON THE NATURE OF NORMALITY OF PLASTIC STRAIN RATE AND CONVEXITY OF YIELD SURFACES IN PLASTICITY.

Within the scope of the purely mechanical theory of plasticity, in a previous paper we have derived two inequalities which place restrictions on the constitutive equation for the rate of plastic strain in a finitely deformed elastic-plastic material. Here we take up the matter further, elaborate on the nature of the previously derived restrictions and obtain some additional results pertaining to the normality of the plastic strain rate and convexity of yeild surfaces. Although in the main our discussions are carried out in the context of finite deformation, the nature of the restrictions for infinitesimal deformation is also examined. A special case of an elastic-plastic material in which the stress response is characterized by the stress rate and that of a rigid-plastic material are given detailed attention.

• Supplemental Notes:
  • Sponsored by Office of Naval Research.
• Corporate Authors:

  University of California, Berkeley

  Department of Mechanical Engineering
  Berkeley, CA  United States  94720-1740
• Authors:
  • Naghdi, P M
  • Trapp, J A
• Publication Date: 1975-1

Media Info

• Features: References;
• Pagination: 24 p.

Subject/Index Terms

• TRT Terms: Deformation curve; Plastic deformation; Structural analysis
• Subject Areas: Marine Transportation; Materials;

Filing Info

• Accession Number: 00084447
• Record Type: Publication
• Source Agency: Ship Structure Committee
• Report/Paper Numbers: NR064-436 Tech. Rpt.
• Contract Numbers: N00014-69A-0100-1008
• Files: TRIS
• Created Date: May 1 1975 12:00AM