FRACTURE CRITERION FOR MATERIALS IN PLASTIC DEFORMATION PROCESSES

The investigation is aimed at establishing the workability of aluminum alloy '7075-T6 in upsetting and rolling at room temperature with reference to occurrence of free-surface cracks. The fracture criterion was established by a plane-strain sheet tension test and an upset test. For obtaining the complete solution in upsetting an improved version of the matrix method was used. Then, a workability chart was constructed by combining the fracture criterion and the complete solution for various friction conditions and several special dimensions. In rolling, a mathematically sound theory was developed for the analysis of spread. With this theory it was possible to predict workability in rolling with reference to edge cracking. The limiting reductions in thickness were given as functions of workpiece dimensions for various friction values. Experimental results demonstrated that the predictions were very good.

• Supplemental Notes:
  • See also AD-700 205.
• Corporate Authors:

  University of California, Berkeley

  Department of Mechanical Engineering
  Berkeley, CA  United States  94720-1740
• Authors:
  • Kobayashi, S
  • Oh, S I
• Publication Date: 1974-8

Media Info

• Pagination: 74 p.

Subject/Index Terms

• TRT Terms: Aluminum alloys; Cracking; Fracture mechanics; Plastic deformation
• Uncontrolled Terms: Crack propagation
• Subject Areas: Marine Transportation; Materials;

Filing Info

• Accession Number: 00095117
• Record Type: Publication
• Source Agency: National Technical Information Service
• Report/Paper Numbers: AFML-TR-74-159 Final Rpt.
• Contract Numbers: F33615-72-C-1645
• Files: TRIS
• Created Date: May 29 1975 12:00AM