Acta Metallurgica Sinica (English Letters) ›› 2009, Vol. 22 ›› Issue (2): 123-130.DOI: 10.1016/S1006-7191(08)60079-4

• Research paper • Previous Articles     Next Articles

Yield criterions of metal plasticity in different stress states

Fengping YANG1, Qin SUN1,Wei HU2   

  1. 1) School of Aeronautics, Northwestern Polytechnical University, Xi'an 710072, China
    2) Institute of Orthopedic Oncology, Tangdu Hospital, Fourth Military Medical University,Xi'an 710038, China
  • Received:2008-05-19 Revised:2008-08-25 Online:2009-04-25 Published:2009-10-10
  • Contact: Fengping YANG

Abstract:

Five types of tensile tests were conducted to study the yield behavior of 2A12-T4 aluminum alloy. Parallel finite element models were built for each test and solved with ABAQUS with different yield criterions. The result shows that any of the four criterions: von Mises yield criterion, Tresca criterion, Twin-Shear criterion and von Mises criterion with hydrostatic pressure correction, overestimates the yield strengths of the specimens. Rather than hydrostatic pressure, Lode stress parameter is the key factor that affects the differences between experimental and simulation results. Based on this concept, a new yield model with Lode dependence modified from von Mises criterion is postulated. Although one more parameter needs to be confirmed, the simulation results of this yield model are better than those of other criterions.

Key words: Yield strength, Lode stress parameter, Hydrostatic pressure, Finite element method (FEM)