Forming Limit Strain of Sheet Metals Subjected to Plane Strain Tension

• Gotoh Manabu

  Department of Mechanical Engineering, Gifu University

• Misawa Masayuki

  Toyota Automobile Co. Ltd.

• Lim Cheal Rok

  Department of Mechanical Engineering, Gifu University

抄録

Experiments on the forming limit strains of several metal sheets are performed exclusively under the (quasi-) plane strain tension. As well known, sheet breaks generally due to localized necking (localized-type instability or bifurcation). All theories predicts that any sheet would break at the tensile strain comparable with its n-value (strain-hardening exponent) under such conditions. It is clarified here why there exist so many materials whose forming limit strains for plane strain tension are not coincident with their n-value. It is verified that the theoretical critical condition for localized necking is basically correct, in which the first-order derivative of the stress-strain relation (the strain-hardening characteristic) of the material plays the decisive role. The conventional n-th power law approximation of the strain-hardening characteristic is not reliable when its first-order derivative must be used. It is emphasized that the strain-hardening characteristic has to be formulated precisely up to its first order derivative when determining the forming limit strain.

収録刊行物

• JSME international journal. Ser. A, Mechanics and material engineering

  JSME international journal. Ser. A, Mechanics and material engineering 36 (2), 172-181, 1993-04-15

  一般社団法人日本機械学会

キーワード

• Plasticity
• Forming limit strain
• Sheet metal
• Plane strain tension
• Localized necking
• Plastic instability
• Strain-hardening characteristics

詳細情報

• CRID: 1571698602110930560
• NII論文ID: 110002964288
• NII書誌ID: AA10888746
• ISSN: 09148809
• 本文言語コード: en
• データソース種別:
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