Numerical and experimental analysis of damage in the single point incremental forming of Aluminum/Copper bilayer sheet

Document Type : Original Article

Authors

1 Assistant Professor, Department of Material and Manufacturing Engineering, University of Mohaghegh Ardabili, Ardabil, Iran

2 Assistant Professor, Department of Mechanical Engineering, Babol Noshirvani University of Technology, Babol, Iran

3 Professor, Department of Mechanical Engineering, Amirkabir University of Technology, Tehran, Iran

Abstract

Incremental forming of metal sheets is one of the new methods of forming, in which the local exertion of forming forces and the absence of a matrix enhances the forming limit of the sheet and extends the flexibility of process in producing of complex geometries. In this research, the forming limit of aluminum/copper bilayer sheets in the single-point incremental forming of different geometries was studied. Considering the instability mechanism of the sheet, the Xue-Wierzbicki damage criterion was used in the form of the VUMAT subroutine of Abaqus in the numerical prediction of the growth and damage initiation of bilayer sheets. Experimental tests showed that the type of geometry has influences on the forming height limit due to the different induced stress and strain states on the sheet. The prediction of the numerical model of the forming height limit on average for different geometries with difference of 8% compared to the experimental tests, which indicates the validity of the numerical model. Accordingly, using the numerical model, the effect of changes in equivalent plastic strain and triaxial stress as crucial variables on the distribution of surface strains and damage was analyzed. Also, cyclic and nonlinear loading in this process was shown by plotting the strain path for different geometries.

Keywords


[1]  Silva M, Nielsen P, Bay N, Martins P. Failure mechanisms in single-point incremental forming of metals. The International Journal of Advanced Manufacturing Technology: 2011; 56: 893-903. doi: 10.1007/s00170-011-3254-1
[2]  Isik K, Silva M, Tekkaya A, Martins P. Formability limits by fracture in sheet metal forming. Journal of Materials Processing Technology: 2014; 214(8): 1557-1565. doi: 10.1016/j.jmatprotec.2014.02.026
[3]  Al-Ghamdi K, Hussain G. Threshold tool-radius condition maximizing the formability in SPIF considering a variety of materials: experimental and FE investigations. International Journal of Machine Tools and Manufacture: 2015; 88: 82-94. doi: 10.1016/j.ijmachtools.2014.09.005
[4]  Mirnia M, Shamsari M. Numerical prediction of failure in single point incremental forming using a phenomenological ductile fracture criterion. Journal of Materials Processing Technology: 2017; 244: 17-43. doi: 10.1016/j.jmatprotec.2017.01.029
[5]  Sakhtemanian M, Honarpisheh R, Amini S. Numerical and experimental study on the layer arrangement in the incremental forming process of explosive-welded low-carbon steel/CP-titanium bimetal sheet. The International Journal of Advanced Manufacturing Technology: 2018; 95(9): 3781-3796. doi: 10.1007/s00170-017-1462-z
[6]  Honarpisheh M, Keimasi M, Alinaghian I. Numerical and experimental study on incremental forming process of Al/Cu bimetals: influence of process parameters on the forming force, dimensional accuracy and thickness variations. Journal of mechanics of materials and structures: 2018; 13(1): 35-51. doi: 10.2140/jomms.2018.13.35
[7] Qin Q, He L, Li C. Control and optimization of bulge defect in incremental forming of cu-Al bimetal. International Journal of Material Forming: 2021;14: 1243–1258. doi: 10.1007/s12289-020-01605-5
[8] Jalali A, Hashemi R, Rajabi M, Tayebi P. Finite element simulations and experimental verifications for forming limit curve determination of two-layer aluminum/brass sheets considering the incremental forming process. Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials Design and Applications: 2022; 236(2): 361-373. doi: 10.1177/14644207211045212
[9] Xue L, Wierzbicki T. Ductile fracture initiation and propagation modeling using damage plasticity theory. Engineering Fracture Mechanics: 2008; 75(11): 3276-3293. doi: 10.1016/j.engfracmech.2007.08.012
[10] Hill R. A theory of the yielding and plastic flow of anisotropic metals. Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences: 1948 May 27;193(1033):281-97. doi: 10.1098/rspa.1948.0045
[11] Xue L. Stress based fracture envelope for damage plastic solids. Engineering Fracture Mechanics: 2009 Feb 1;76(3):419-38. doi: 10.1016/j.engfracmech.2008.11.010
[12] Zahedi A, Mollaei Dariani B, Mirnia M. Experimental determination and numerical prediction of necking and fracture forming limit curves of laminated Al/Cu sheets using a damage plasticity model. International Journal of Mechanical Sciences: 2019; 153: 358-413. doi: 10.1016/j.ijmecsci.2019.02.002