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Analysis of the Size Effect on Springback Behavior in Micro‐ S caled U‐ B ending Process of Sheet Metals
Author(s) -
Wang Jilai,
Fu Mingwang,
Ran Jiaqi
Publication year - 2014
Publication title -
advanced engineering materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.938
H-Index - 114
eISSN - 1527-2648
pISSN - 1438-1656
DOI - 10.1002/adem.201300275
Subject(s) - sheet metal , materials science , bending , bent molecular geometry , composite material , grain size , die (integrated circuit) , forming processes , radius , microstructure , stress (linguistics) , structural engineering , alloy , deformation (meteorology) , bend radius , ultimate tensile strength , metallurgy , engineering , nanotechnology , linguistics , philosophy , computer security , computer science
In the micro‐bending process of sheet metals, springback caused by the considerable elastic recovery during unloading has a significant effect on the dimension precision of micro‐bent sheet metal parts. In design of micro‐bent parts and bending process, this phenomenon needs to be considered. However, the traditional well‐established knowledge for analysis of macro‐scaled sheet metal bending processes may not be very suitable and efficient in analysis of micro‐scaled sheet metal bending due to the geometry and microstructure size effects in the process. To explore the unloading springback of sheet metals after micro‐bending, the experimental studies on the interactive influence of a few significant parameters including sheet thickness, grain size, and punch radius on the springback in micro U‐bending process of copper alloy sheets were conducted. An appropriate constitutive model based on the surface layer model, which is widely used in micro‐scaled forming processes, is proposed to predict the amount of springback and the relationship among these parameters is further established. The research shows that the springback angle generally increases with the decreasing sheet thickness, and for different punch radii, the springback angle has different variation trends for the sheet metals with different grain sizes. The developed analysis method is verified via the comparison of the calculated stress–strain curves with the tensile test results of three kinds of copper alloy sheets. The findings on how the size effects affect the springback behaviors of in micro‐bending process are validated by the experimental results, finite element simulation, and the comparison in‐between.