Results 261 to 270 of about 1,630,631 (307)
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Soviet Studies in Literature, 1970
I should like to speak somewhat more sharply about the modern story. It is easy enough to show indignation, take me by the hand, and point to the quality of a few, shall we say, remarkable stories that have appeared recently. But I am deliberately exaggerating when I assert that the story today is inadequate and untenable.
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I should like to speak somewhat more sharply about the modern story. It is easy enough to show indignation, take me by the hand, and point to the quality of a few, shall we say, remarkable stories that have appeared recently. But I am deliberately exaggerating when I assert that the story today is inadequate and untenable.
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Forming limit analysis of hemispherical-punch stretch forming
Journal of Materials Processing Technology, 2001Abstract This paper combines elastic–plastic membrane finite elements and forming limit theory to determine the limiting dome height of axisymmetric stretch forming. The elastic–plastic finite element approach is based on the flow rule associated with Hill’s quadratic yield criterion for anisotropic material.
Tung-Sheng Yang, Tze-Chi Hsu
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2004
In this work, the Marciniak and Kuczynski model (MK) will be reviewed and will be generalized to a more general approach for the calculation of forming limit diagrams. In the new model we will account for all directions of the imperfection. This new approach has been used to calculate the theoretical FLDs (forming limit diagrams) for Vonmises, Barlat ...
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In this work, the Marciniak and Kuczynski model (MK) will be reviewed and will be generalized to a more general approach for the calculation of forming limit diagrams. In the new model we will account for all directions of the imperfection. This new approach has been used to calculate the theoretical FLDs (forming limit diagrams) for Vonmises, Barlat ...
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Forming Limit Curves in Single Point Incremental Forming
CIRP Annals, 2007New experimental data is presented on Forming Limits in Single Point Incremental Forming (SPIF), which is a sheet metal forming process which does not require dies. A Box-Behnken Design of Experiment is used to develop the experimental plan and analyze data. In former work, the most critical factors affecting Single Point Incremental Forming were found
M. Ham, J. Jeswiet
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Calculations of forming limit diagrams
Metallurgical Transactions A, 1990The right-hand side of the forming limit diagram (FLD) was calculated using a Marciniak-Kuczynski analysis with a nonquadratic anisotropic yield criterion. Effects of changing the strain-hardening exponent, n, strain-rate exponent, m, strain ratio, R, stress exponent in the anisotropic yield criterion, a, and the inhomogeneity factor, f, were explored.
Alejandro Graf, William F. Hosford
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Forming Limit Criteria — Sheets
1978First introduced in 1963, forming limit diagrams (FLDs) have been empirically constructed to describe the strain states, or combinations of major (e1) and minor (e2) principal strains, at which a highly localized zone of thinning or necking becomes visible in the surface of sheet metal. Laboratory rigid-punch and pressshop experiments have shown that a
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Variability of forming limit curves
International Journal of Mechanical Sciences, 1974Summary The forming limit curve indicates the maximum uniform strain which can be achieved in an element of a sheet which is strained in a proportional biaxial straining process; it refers to the strain in a region adjacent to, but not within, any area of localized straining associated with rupture.
H. van Minh, R. Sowerby, J.L. Duncan
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2011
In a deforming sheet, the strain state is defined as the ratio between minor strain and major strain. The formability depends on this strain state and can be expressed as the so-called forming limit curve (FLC). In complex strain states the deformation is limited by an instability just as in a tensile test. In cases of negative minor strain this can be
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In a deforming sheet, the strain state is defined as the ratio between minor strain and major strain. The formability depends on this strain state and can be expressed as the so-called forming limit curve (FLC). In complex strain states the deformation is limited by an instability just as in a tensile test. In cases of negative minor strain this can be
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1978
The maximum strain that the sheet metal can suffer in stretch-forming processes is limited by the phenomena of strain localization and fracture. Both are strictly connected with the stability loss of the workpiece. Different possible modes of instability are discussed in the paper. Also the post-stability stages of the forming process are analyzed.
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The maximum strain that the sheet metal can suffer in stretch-forming processes is limited by the phenomena of strain localization and fracture. Both are strictly connected with the stability loss of the workpiece. Different possible modes of instability are discussed in the paper. Also the post-stability stages of the forming process are analyzed.
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