Damage and fracture during sheet-metal forming of alloy 718
| Autor: | Mats Oldenburg, Lluís Pérez Caro, Eva-Lis Odenberger, Kristian Haller, Mikael Schill |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
0209 industrial biotechnology
Digital image correlation Yield (engineering) Materials science Non-linear acoustics GISSMO 02 engineering and technology Nickel alloys Strain Drawing (forming) 020901 industrial engineering & automation 0203 mechanical engineering Alloy 718 Naturvetenskap Formability von Mises yield criterion Optimisation General Materials Science Material failure theory Sheet metal Composite material Plane stress Non-linear acoustic technique Metal forming Shear (sheet metal) Damage Fracture 020303 mechanical engineering & transports Aircraft engines visual_art visual_art.visual_art_medium Anisotropy Natural Sciences Optimisations Forecasting |
| Zdroj: | International Journal of Material Forming. 13:15-28 |
| ISSN: | 1960-6214 1960-6206 |
| DOI: | 10.1007/s12289-018-01461-4 |
| Popis: | Forming nickel-based superalloy aero-engine components is a challenging process, largely because of the risk of high degree of springback and issues with formability. In the forming tests conducted on alloy 718 at room temperature, open fractures are observed in the drawbead regions, which are not predicted while evaluating the formability using the traditional forming-limit diagram (FLD). This highlights the importance of an accurate prediction of failure during forming as, in some cases, may severely influence the springback and thereby the accuracy of the predicted shape distortions, leading the final shape of the formed component out of tolerance. In this study, the generalised incremental stress-state dependent damage model (GISSMO) is coupled with the isotropic von Mises and the anisotropic Barlat Yld2000-2D yield criteria to predict the material failure in the forming simulations conducted on alloy 718 using LS-DYNA. Their effect on the predicted effective plastic strains and shape deviations is discussed. The failure and instability strains needed to calibrate the GISSMO are directly obtained from digital image correlation (DIC) measurements in four different specimen geometries i.e. tensile, plane strain, shear, and biaxial. The damage distribution over the drawbeads is measured using a non-linear acoustic technique for validation purposes. The numerical simulations accurately predict failure at the same regions as those observed in the experimental forming tests. The expected distribution of the damage over the drawbeads is in accordance with the experimental measurements. The results highlight the potential of considering DIC to calibrate the GISSMO in combination with an anisotropic material model for forming simulations in alloy 718. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full text from SpringerLink