PLASTIC FLOW AROUND AN EXPANDING CRACK

The problem of a central crack expanding at both ends in a uniformly stretched plate is examined for the case when the material along the lines of expected crack extension flows plastically and moves with the crack at a different velocity. The variations of the plastic zone size with crack speeds and applied stress to yield stress ratio P/Y are determined. For a given value of P/Y, and increase in crack velocity is found to cause a decrease in the length of the traveling plastic zone. The amount of energy released by the moving crack is also estimated for the purely elastic and elastic-plastic crack models and is shown to diminish to zero at the Rayleigh wave speed. The present results support the expected conclusion that for a given amount of available energy a crack can be driven at a high speed without plastic dissipation. This effect is demonstrated quantitatively for the strip model of an expanding crack.

• Corporate Authors:

  Lehigh University

  Institute of Fracture and Solid Mechanics
  Bethlehem, PA  United States  18015
• Authors:
  • Embley, G T
  • SIH, G C
• Publication Date: 1971-8

Media Info

• Features: References;
• Pagination: 24 p.

Subject/Index Terms

• TRT Terms: Cracking; Elasticity (Mechanics); Plasticity; Structural analysis
• Uncontrolled Terms: Crack propagation
• Subject Areas: Marine Transportation; Materials;

Filing Info

• Accession Number: 00032215
• Record Type: Publication
• Source Agency: Ship Structure Committee
• Report/Paper Numbers: IFSM-71-7
• Files: TRIS
• Created Date: Apr 21 1973 12:00AM