Capability of iterative learning control and influence of the material properties on the improvement of the geometrical accuracy in incremental sheet forming process

Incremental Sheet Forming (ISF) is a flexible technology that allows the deformation of blank sheets without the need of complex and high cost tools or equipments. One of the main lacks of ISF is the geometrical accuracy which is not comparable with the one achieved by using traditional sheet stamping processes. There are several approaches proposed to enhance this aspect and among them the Authors have developed a method based on an Iterative Learning Control (ILC). ILC consists of a cyclic and progressive error compensation method that improves the quality of the manufactured parts. ILC has been proved to be capable for optimising the production of parts with tight tolerances when dealing with ductile materials (aluminium and steel alloys) and small deformations. In this paper, the method was tested to investigate its capability in a virtual environment. The suggested compensations were checked with Finite Element Method (FEM) so to reduce the number of parts to be manufactured saving time and costs. Moreover, the algorithm was tested considering both a difficult to form material (titanium alloy) and high deformation conditions. The results demonstrated how the precision of ISF processes depends on the blank material properties. Moreover, the capabilities of ILC are shown and discussed.

[1]  M. Schikorra,et al.  Metal forming progress since 2000 , 2008 .

[2]  Paul A. Meehan,et al.  Multi-pass deformation design for incremental sheet forming: Analytical modeling, finite element analysis and experimental validation , 2014 .

[3]  Johan Verbert,et al.  Laser Assisted Incremental Forming: Formability and Accuracy Improvement , 2007 .

[4]  Jack Jeswiet,et al.  Forming Limit Curves in Single Point Incremental Forming , 2007 .

[5]  Julian M. Allwood,et al.  Closed-loop feedback control of product properties in flexible metal forming processes with mobile tools , 2009 .

[6]  Elisabetta Ceretti,et al.  Part precision improvement in incremental sheet forming of not axisymmetric parts using an artificial cognitive system , 2015 .

[7]  Aldo Attanasio,et al.  On forces, formability and geometrical error in metal incremental sheet forming , 2011 .

[8]  Horst Meier,et al.  Increasing the part accuracy in dieless robot-based incremental sheet metal forming , 2009 .

[9]  Elisabetta Ceretti,et al.  Improving Accuracy in Aluminum Incremental Sheet Forming of Complex Geometries Using Iterative Learning Control , 2015 .

[10]  Taylan Altan,et al.  Sheet metal forming at elevated temperatures , 2006 .

[11]  Elisabetta Ceretti,et al.  Application of artificial cognitive system to incremental sheet forming machine tools for part precision improvement , 2015 .

[12]  A. Iqbal,et al.  Response surface analysis of cold formability of polymers in Incremental Sheet Forming: Effect of parameters and associated thermal softening , 2016 .

[13]  A. H. van den Boogaard,et al.  The technology of Incremental Sheet Forming¿A brief review of the history , 2010 .

[14]  Elisabetta Ceretti,et al.  Preliminary results on Ti incremental sheet forming (ISF) of biomedical devices: biocompatibility, surface finishing and treatment , 2012 .

[15]  Bert Lauwers,et al.  Study on the achievable accuracy in single point incremental forming , 2007 .

[16]  Matthieu Rauch,et al.  Tool path programming optimization for incremental sheet forming applications , 2009, Comput. Aided Des..

[17]  Jianhua Mo,et al.  Tool path correction algorithm for single-point incremental forming of sheet metal , 2013 .

[18]  Aldo Attanasio,et al.  DESIGN OF AN EQUIPMENT FOR FORCES MEASUREMENT IN TPIF PROCESS , 2008 .

[19]  Junchao Li,et al.  Numerical simulation and experimental investigation of incremental sheet forming with an elastic support , 2014 .

[20]  Bert Lauwers,et al.  Achievable accuracy in single point incremental forming: case studies , 2005 .

[21]  Joost Duflou,et al.  Study of the geometrical inaccuracy on a SPIF two-slope pyramid by finite element simulations , 2012 .

[22]  A. Iqbal,et al.  High-Speed Incremental Forming Process: A Trade-Off Between Formability and Time Efficiency , 2015 .

[23]  Michael J. Grimble,et al.  Iterative Learning Control for Deterministic Systems , 1992 .

[24]  Joost Duflou,et al.  Asymmetric single point incremental forming of sheet metal , 2005 .

[25]  Nimbalkar D.H.  Review of Incremental Forming of Sheet Metal Components , 2013 .

[26]  Elisabetta Ceretti,et al.  Development of Tool Path Correction Algorithm in Incremental Sheet Forming , 2014 .

[27]  Fabrizio Micari,et al.  Analysis of Material Formability in Incremental Forming , 2002 .

[28]  Markus Bambach,et al.  Strategies to improve the geometric accuracy in asymmetric single point incremental forming , 2009, Prod. Eng..

[29]  Dongkai Xu,et al.  Mechanism investigation for the influence of tool rotation and laser surface texturing (LST) on formability in single point incremental forming , 2013 .

[30]  Joost R. Duflou,et al.  Process window enhancement for single point incremental forming through multi-step toolpaths , 2008 .

[31]  Fabrizio Micari,et al.  Shape and dimensional accuracy in Single Point Incremental Forming: State of the art and future trends , 2007 .

[32]  Joost R. Duflou,et al.  Improved SPIF performance through dynamic local heating , 2008 .

[33]  I. Ferrer,et al.  The Effect of Process Parameters on the Energy Consumption in Single Point Incremental Forming , 2013 .

[34]  Jian Cao,et al.  A new methodology for multi-pass single point incremental forming with mixed toolpaths , 2011 .

[35]  Isabel Bagudanch,et al.  Fabrication of a biopsy meso-forceps prototype with incremental sheet forming variants , 2013 .

[36]  Wang Bin,et al.  A multipass incremental sheet forming strategy of a car taillight bracket , 2013 .

[37]  Elisabetta Ceretti,et al.  Rapid Prototyping techniques for individualized medical prosthesis manufacturing , 2011 .