Localized thinning, fracture and formability aluminium sheet alloys in biaxial tension

Prediction of fracture limit curves in sheet metals using a void growth and coalescence model

“…The validity of the present model is realized through comparison with the limited experimental FLCF's existing in the literature (Grumbach and Sanz, 1972;LeRoy and Embury, 1977;Jain et al, 1999;Barata Marques and Baptista, 1992;Beaver, 1982). These FLCF's have been all determined experimentally by almost the same technique originally due to Hecker (1975).…”

“…ε 1n and ε 2n . In other words, this means that voids do not play a decisive role leading to fracture before the onset of necking as observed experimentally for some alloys (Jain et al, 1999;Beaver, 1982;Thomson and Nayak, 1980). For continuous nucleation a similar concept applies in defining initial conditions with f i = 0 while assigning reasonable values for f N and ε prof .…”

“…Further straining beyond localized necking ends up by fracture and a forming limit curve at fracture (FLCF) may be also constructed. For many sheet metals the FLCF may represent higher levels of limit strains compared to those prescribed by the FLCN (Grumbach and Sanz, 1972;LeRoy and Embury, 1977;Jain et al, 1999;Barata Marques and Baptista, 1992;Beaver, 1982). The differences between both types of curves decay for strain paths approaching equibiaxial stretching.…”

“…Few experimentally determined FLCF are found in the literature for steels (Grumbach and Sanz, 1972; Barata Marques E-mail address: a.r.ragab@link.net. and Baptista, 1992) and aluminums (LeRoy and Embury, 1977;Jain et al, 1999;Beaver, 1982). Attempts are made to predict them by applying ductile fracture criteria to biaxial straining processes.…”

Shear Localization and Damage in AA5754 Aluminum Alloy Sheets

“…An evidence of PLC effect is the serrated flow in the tensile curves which occurs over a wide range of temperatures and strain rates. It is also well known that Al-Mg alloys fail by localization of flow into bands of intense shear (Ref [1][2][3][4][5][6]. However, the mechanism governing the formation of shear bands is still controversial in the literature and current models cannot account for many experimental observations ( Ref 7).…”