Localized Necking: An Inclined Imperfection Model.
Abstract
The Marciniak and Kuczynski (M-K) analysis, which associates localized necking in sheet metal with pre-existing imperfections, has been modified such that the imperfection or groove is inclined (rather than normal) to the major principal strain axes. The analysis, which is closely related to the calculations of Hutchinson and Neale, takes into account the requirement for localized necking that a direction of zero-extension is inclined for strain states between uniaxial tension and plane strain. Based on the inclined imperfection model, calculations are presented for the negative minor strain regime of a forming limit diagram showing the dependence of localized necking on work hardening, strain rate sensitivity, plastic anisotropy, and imperfection factor. Theoretical calculations of forming limit curves indicate good agreement between the model and previously obtained experimental data for several alloys. Such agreement is obtained for realistically small imperfections, although the limit strains predicted by the model itself are relatively insensitive to the magnitude of the imperfection. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1981
- Accession Number
- ADA107137
Entities
People
- Ashish Ghosh
- Donald A. Koss
- K. S. Chan
Organizations
- Michigan Technological University