A variable strain hardening model for anisotropic sheet metals
16 May 2012-Journal of Strain Analysis for Engineering Design (SAGE Publications)-Vol. 47, Iss: 5, pp 289-296
TL;DR: In this article, a phenomenological approach is proposed to model the influence of texture-induced anisotropy in the variation of strain hardening characteristics of a sheet material, and the results showed that a variable strain-hardening exponent provided greater accuracy of numerical prediction than the existing isotropic model.
Abstract: A phenomenological approach is proposed to model the influence of texture-induced anisotropy in the variation of strain hardening characteristics of a sheet material The variation of uniaxial strain hardening exponent with rolling direction is modelled using existing anisotropic yield criteria assuming power law strain hardening behaviour The model is extended to the biaxial region to predict the effective strain hardening exponent with the assumption of constant plastic work The prediction of both uniaxial and biaxial strain hardening is compared with the experimental data available in the literature It is observed that a variable strain hardening exponent provided greater accuracy of numerical prediction than the existing isotropic model The accuracy of the proposed model is dependent on the yield criteria and the flow rule used for the modelling
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TL;DR: In this paper, the authors investigated the effect of the texture on the normal anisotropy of steel sheets and found a significant dependence of the R-value and texture on strain and strain path.
8 citations
TL;DR: In this article, varying widths of low carbon steel sheets were punched stretched under laboratory conditions, and thinning during punching was measured at various locations along the steel sheets, showing that thinning is a function of the strain path followed by the sheet.
Abstract: Thinning during forming is often considered a failure criterion in the metal forming industry. It is believed that a critical amount of thinning takes place in a sheet metal before failure. In this study, varying widths of low-carbon steel sheets were punch stretched under laboratory conditions. Thinning during punch stretching was measured at various locations along the steel sheets. These measurements demonstrated that thinning during forming is not constant, but that it is a function of the strain path followed by the sheet. Hence, thinning should not be used as a failure criterion during forming of sheet metals.
6 citations
6 citations
"A variable strain hardening model f..." refers background in this paper
...The influence of anisotropy on the yield strength (initiation of plastic deformation) can be modelled directly from experimental data.(6,7) However, anisotropic yield criteria based on the continuum approach, which account for the texture effect using simple mechanical tests like plastic strain ratio, R (width strain/thickness strain) are more practical(8) for low-temperature, time-independent multiaxial plasticity and are widely used....
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09 Aug 2005
TL;DR: The Numisheet 2005 Benchmark as discussed by the authors consists of a two-stage forming process performed on four materials (three steels and one aluminum), and the results are repeatable and consistent with expectations.
Abstract: The Numisheet 2005 Benchmark ♯3 consists of a two stage forming process performed on four materials (three steels and one aluminum). Stage 1 consists of forming channel sections in a channel draw die with variable penetration draw beads, and is described in detail in another report. In Stage 2, described here, the samples from Stage 1 are trimmed and subjected to near plane strain Marciniak style cup test. The plane straining is performed in 0 ° and 90 ° orientations. After failure limits for the cup depths are determined, trimmed samples from Stage 1 are strained to specific cup depths (less than the depth of failure) and stresses are measured in situ using a unique X‐ray diffraction technique. The results are repeatable and consistent with expectations. The goal of this benchmark is to check not only the strain achieved during a two stage forming process, but also to develop data that include the stresses achieved. These results may then be used to further test the ability of numerical models to predict...
6 citations
DOI•
01 Jan 1994
2 citations
"A variable strain hardening model f..." refers background in this paper
...The chances of recrystallization nuclei of the {111} texture component overcoming the inhibition by AlN precipitates is high, resulting in strong {111} texture.(3) The texture induced by mechanical working and subsequent annealing results in anisotropy of mechanical properties in sheet metals....
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