Bending of sheet

Marciniak, Zbigniew; Duncan, J.L.; Hu, S. Jack

doi:10.1016/b978-075065300-8/50009-1

Cited by 78 publications

(120 citation statements)

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“…In summary, localized necking and shear failure of the uncracked ligament will likely be favored at 300°C, where a decrease in strain hardening and increase in damage-induced fracture strain promotes localization [13,19,20]. Given the small value of strain hardening in irradiated Zircaloy [21], it is not surprising that high-burnup cladding, such as that shown in Fig.…”

Section: On the Failure Processmentioning

confidence: 99%

On the Embrittlement of Zircaloy-4 Under RIA-Relevant Conditions

Daum

Majumdar

et al. 2002

Zirconium in the Nuclear Industry: Thirteenth International Symposium

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ABSTRACT:The extended use of Zircaloy cladding in light water reactors degrades its mechanical properties by a combination of irradiation embrittlement, coolant-side oxidation, hydrogen pickup, and hydride formation. The hydrides are usually concentrated in the form of a dense layer or rim near the cooler outer surface of the cladding. Utilizing plane-strain ringstretch tests to approximate the loading path in a reactivity-initiated accident (RIA) transient, we examined the influence of a hydride rim on the fracture behavior of unirradiated Zircaloy-4 cladding at room temperature and 300°C. Failure is sensitive to hydride-rim thickness such that cladding tubes with a hydride-rim thickness >100 µm (≈700 wppm total hydrogen) exhibit brittle behavior, while those with a thickness <90 µm (≈600 wppm) remain ductile. The mechanism of failure is identified as strain-induced crack initiation within the hydride rim and failure within the uncracked ligament due to either a shear instability or damage-induced fracture. We also report some preliminary results of the uniaxial tensile behavior of low-Sn Zircaloy-4 cladding tubes in a cold-worked, stress-relieved condition in the transverse (hoop) direction at strain rates of 0.001/s and 0.2/s and temperatures of 26-400°C.

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Section: On the Failure Processmentioning

confidence: 99%

On the Embrittlement of Zircaloy-4 Under RIA-Relevant Conditions

Daum

Majumdar

et al. 2002

Zirconium in the Nuclear Industry: Thirteenth International Symposium

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“…Substituting the strain values calculated in the Von-Mises equation, the effective strain is calculated as 0.365 [8]. The Bulge Test Setup is designed based on the calculated effective strain of 0.365.…”

Section: (1)mentioning

confidence: 99%

“…The volume preservation can also be written for the entire sheet metal specimen. The volume preservation mandates that the volume of the specimen before deformation to be the same as the volume of the bulged specimen after deformation [8].…”

Section: (1)mentioning

confidence: 99%

“…The radius of curvature of the bulge can be calculated in terms of the radius of the die cavity R and the bulge depth as [8] …”

Section: (1)mentioning

confidence: 99%

“…The Bulge Test Setup is designed based on the calculated effective strain of 0.365. Using power law, the effective stress is calculated based on the calculated effective strain  and the material properties of the specimen [8]. (9) where K is the strength coefficient (or K-value) and n is the strain hardening exponent (or nvalue) of the material tested.…”

Section: (1)mentioning

confidence: 99%

See 2 more Smart Citations

Learning Experience in Designing a Hydraulic Bulge Test Setup for Material Properties Characterization

Jaia¹,

Matin²

2015 ASEE Annual Conference and Exposition Proceedings

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Analytical approach to investigate the effects of through-thickness stress on springback in bending of isotropic sheet metal

Movahedi,

Gerdooei

2024

Int J Adv Manuf Technol

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Within contemporary sheet metal forming processes like electromagnetic forming, the sheet experiences pronounced out-of-plane compression stress. This study focuses on the predicting the springback in the bending of an isotropic sheet metal in the presence of through-thickness compressive normal stress. In the analytical method, the longitudinal stress distribution across sheet thickness was calculated via equilibrium equations and the associated ow rule in incremental plasticity based on the power law hardening model, obtaining the reverse bending moment. During the unloading phase, the external load was lifted, and the springback angle was estimated by assuming linear elastic behavior and neglecting the Bauschinger effect, employing the superposition method. A case study was conducted on an aluminum alloy sheet for different compressive stresses and bend curvatures. Subsequently, the reverse bending moments and springback angles obtained for each case were compared to the numerical outcomes from nite element (FE) modeling. Analytical results indicate that elevating the compressive normal stress on the sheet surface to 75% and 100% of the yield stress will lead to a reduction in springback by 17.4% and 32%, respectively. At the compressive normal stress of 75% of the yield stress, the numerical model exhibited a 4.4% difference from the analytical model. For the validation of the analytical model, a four-point bending test was conducted with varying initial bend curvatures and angles. This involved comparing the experimental springback angle and curvature with both numerical and analytical predictions. In comparison, both the numerical and analytical models demonstrated strong agreement with the experimental results.

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Bending of sheet

Cited by 78 publications

References 0 publications

On the Embrittlement of Zircaloy-4 Under RIA-Relevant Conditions

On the Embrittlement of Zircaloy-4 Under RIA-Relevant Conditions

Learning Experience in Designing a Hydraulic Bulge Test Setup for Material Properties Characterization

Analytical approach to investigate the effects of through-thickness stress on springback in bending of isotropic sheet metal

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