• Title/Summary/Keyword: Diffuse Nocking

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A Prediction of Bursting Failure in Tube Hydroforming Process Based on Necking Conditions (네킹발생조건에 의한 관재 액압성형 공정에서의 터짐 불량 예측)

  • 김상우;김정;박훈재;강범수
    • Transactions of Materials Processing
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    • v.13 no.7
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    • pp.629-634
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    • 2004
  • Based on plastic instability, analytical prediction of bursting failure on tube hydroforming processes under combined infernal pressure and independent axial feeding is carried out. Bursting is irrecoverable phenomenon due to local instability under excessive tensile stresses. In order to predict the bursting failure, three different classical necking criteria such as diffuse necking criterion for sheet and tube, local necking criterion for sheet are introduced. The incremental theory of plasticity for anisotropic material is adopted and then the hydroforming limit and bursting failure diagram with respect to axial feeding and hydraulic pressure are presented. In addition, the influences of the material properties such as anisotropy Parameter, strain hardening exponent and strength coefficient on bursting Pressure are investigated. As results of the above approach, the hydroforming limit in view of bursting failure is verified with experimental results.