Evoution of Yield surfaces: Past and Future Trend - Part 3

 My last two posts on this series

Part- 1 (node/9016) and

Part- 2 (node/9073)

were mainly focussed on the tension–torsion (σ11–√3σ12) stress space. This paper will be the final post on this series and will focus mainly on the behavior of  both of these alloys under tension–tension (σ11–σ22)space and conclude this ongoing research.

Abstract.

Subsequent yield surfaces for aluminum alloys are determined for three
proportional loading paths (i.e., axial, hoop, and combined hoop and
axial stress) using 10 με deviation from linearity as the definition of
yield. This paper is in continuation with Parts I and II of the author’s
previous papers on subsequent yield surfaces under tension–torsion (σ11–√3σ12)
stress space using similar small offset definition of yield. In the
current paper comprehensive experimental results on subsequent yield
surfaces under tension–tension (σ11–σ22) stress space are presented. Comparison of subsequent yield surfaces under (σ11–√3σ12)
stress space, investigated in the earlier papers, clearly indicated
distinctive hardening behavior under various loading paths. However,
subsequent yield surfaces for Al 6061–T 6511 (a low work hardening
alloy) showed contraction and negative cross-effect with finite
deformation as compared to the annealed 1100 Al (a high work hardening
alloy) where expansion and positive cross-effect was observed.

Reference: 

 Evolution of subsequent yield surfaces and elastic constants with finite plastic deformation. Part III: Yield surface in tension–tension stress space (Al 6061–T 6511 and annealed 1100 Al) 

International Journal of Plasticity, Volume 26, Issue 10, October 2010, Pages 1432-1441
Akhtar S. Khan, Amit Pandey, Thomas Stoughton