On pre-straining and the evolution of material anisotropy in sheet metals

Numerical study on the influence of initial anisotropy on optimal blank shape

“…Due to the complexity involved in its implementation in finite element simulations and increased computation time, generally deformation induced anisotropy is neglected in industrial applications. Moreover, considering only the initial anisotropy produces results in close agreement to the experimental data [4,5].…”

Advances in experiments on metal sheets and tubes in support of constitutive modeling and forming simulations

“…Recently, Wu et al (2005b) have shown that the conventional methodology for determining material anisotropy (i.e., on the basis of flow stress measurements) overestimates the prestraining effect; they concluded that the degree of material anisotropy depends on the strain level at which the tensile flow stresses are measured. The experiments carried out using AA6111 alloy demonstrate that prestraining mainly affects the elastic-plastic transition at yield and that the apparent change in the directionality of the axes of orthotropy is not validated by the r-value measurements.…”

Investigation of subsequent viscoplastic deformation of austenitic stainless steel subjected to cyclic preloading

“…Mollica et al (2001) developed a general three dimensional model, which can reproduce the stress-strain response at loading reversals and can be applied to more general changes in loading direction. Deformation induced anisotropy, which leads to different subsequent deformations depending on the loading direction has also been investigated (Ishikawa, 1997;Ishikawa and Sasaki, 1998;Kalidindi, 2001;Yao and Cao, 2002;Tuğcu et al, 2002;Garmestani et al, 2002;Wu, 2002;Chiang et al, 2002;Geng et al, 2002;Wu et al, 2003;Kowalczyk and Gambin, 2004;Tsakmakis, 2004;Häusler et al, 2004;Bron and Besson, 2004;Vincent et al, 2004;Cazacu and Barlet, 2004;Kuwabara et al, 2005;Wu et al, 2005;Barlet et al, 2005). Kalidindi (2001) reviewed and summarized models of anisotropic strain hardening and deformation textures in low stacking fault energy fcc metals and reported a new approach in modeling the deformation behavior of the materials.…”