TY - JOUR
T1 - Method for prediction of forming limit height in multistep incremental forming with real-time decision making
AU - Filho, Paulo Sergio Olivio
AU - Olivio, Émillyn Ferreira Trevisani
AU - Nikhare, Chetan P.
AU - Valle, Pablo Deivid
AU - Marcondes, Paulo Victor Prestes
N1 - Funding Information:
This research was supported by CNPq (Brazil).
Publisher Copyright:
© 2022 The Society of Manufacturing Engineers
PY - 2023/1/6
Y1 - 2023/1/6
N2 - The multistep incremental forming is a complex process that requires good control of process parameters to create parts without fractures or cracks. In general, the failure prediction in this process is restricted to experiments and applications in finite element simulations. This paper presents an approach to real-time failure prediction in multistep incremental forming from step-by-step strain analyses. Previous single point incremental forming (SPIF) studies have been applied to BH180GI steel at various thicknesses to obtain data on maximum strain, critical wall angles, and the fracture forming limit line for the material. These data were used as a basis for preventing and predicting failure. The experiments were carried out with steps from 30° to 90° in increments of every 10°, totaling 7 steps achieving higher forming heights. From the angle of 60° onwards, measurements of strain were performed step by step and compared with the fracture forming limit line for each material thickness. When the strain was equal or exceeded the fracture forming limit line and the critical fracture thickness, geometry parts, and path corrections were imposed to minimize local strain ensuring a product without fracture. The results showed that the methodology and the corrections imposed prevented the failure and ensured greater formability of the material. This leads to a minimum thickness of 0.098 mm in the wall of the material, in addition to indicating the presence of a maximum limit of the deformed surface area of the material. This indicated a limit for which it is possible to apply the distribution of strain in the material at different forming heights and radius of the part. For the computer simulations, the mechanical properties, constitutive laws, isotropic hardening and a ductile damage criterion based on fracture forming limit line (FFL) with the fracture energy of the material for failure prediction were applied. These data were fed to the numerical model using an explicit integration approach, with a shell element (S4R) with reduced integration and adequate refining. The simulations in multistep incremental forming were efficient and were able to demonstrate the efficiency of this methodology with the application of corrections in geometry and the path in real-time.
AB - The multistep incremental forming is a complex process that requires good control of process parameters to create parts without fractures or cracks. In general, the failure prediction in this process is restricted to experiments and applications in finite element simulations. This paper presents an approach to real-time failure prediction in multistep incremental forming from step-by-step strain analyses. Previous single point incremental forming (SPIF) studies have been applied to BH180GI steel at various thicknesses to obtain data on maximum strain, critical wall angles, and the fracture forming limit line for the material. These data were used as a basis for preventing and predicting failure. The experiments were carried out with steps from 30° to 90° in increments of every 10°, totaling 7 steps achieving higher forming heights. From the angle of 60° onwards, measurements of strain were performed step by step and compared with the fracture forming limit line for each material thickness. When the strain was equal or exceeded the fracture forming limit line and the critical fracture thickness, geometry parts, and path corrections were imposed to minimize local strain ensuring a product without fracture. The results showed that the methodology and the corrections imposed prevented the failure and ensured greater formability of the material. This leads to a minimum thickness of 0.098 mm in the wall of the material, in addition to indicating the presence of a maximum limit of the deformed surface area of the material. This indicated a limit for which it is possible to apply the distribution of strain in the material at different forming heights and radius of the part. For the computer simulations, the mechanical properties, constitutive laws, isotropic hardening and a ductile damage criterion based on fracture forming limit line (FFL) with the fracture energy of the material for failure prediction were applied. These data were fed to the numerical model using an explicit integration approach, with a shell element (S4R) with reduced integration and adequate refining. The simulations in multistep incremental forming were efficient and were able to demonstrate the efficiency of this methodology with the application of corrections in geometry and the path in real-time.
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U2 - 10.1016/j.jmapro.2022.11.052
DO - 10.1016/j.jmapro.2022.11.052
M3 - Article
AN - SCOPUS:85143152051
SN - 1526-6125
VL - 85
SP - 246
EP - 261
JO - Journal of Manufacturing Processes
JF - Journal of Manufacturing Processes
ER -