Sustainable Manufacturing Group

Incremental sheet forming machine (research rig)

Incremental Sheet Forming

Incremental Sheet Forming (ISF) is a modern flexible process for forming sheet metal. An indenter pushes into the surface of the sheet causing a highly localised plastic deformation. A 3D shape can then be formed incrementally by moving the indenter progressively deeper into the sheet along a contour path or similar (see video - download 2.4Mb .wmv file).

The process does not use dies and is therefore cheaper and ecologically favourable for customisation and small batch sizes than processes such as pressing or deep drawing. ISF is recognised as a sustainable manufacturing process because it has the potential to be used for localised production, where smaller machines are located closer to the destination for final use of the product than conventional mass production, reducing transportation distances. ISF can also be used for repair or replacement of damaged or obsolete sheet metal parts.

Aims

To understand the process mechanics and expand the process capabilities in order to develop a flexible manufacturing system that is capable of achieving the specifications of typical sheet metal applications, and to investigate the applicability of ISF to a broader range of materials. To achieve these goals, the project seeks to:

• improve understanding of deformation mechanics and the factors influencing forming limits
• measure and predict forces on the indenter
• investigate the applicability of ISF to a group of materials not previously tried; sandwich panels

The technology

The project is based on a specialised ISF machine commissioned at the Institute for Manufacturing in October 2004. The machine was designed and built in Cambridge University Engineering Department and is the first dedicated machine built outside Japan. Unique features include a built-in force measurement system, rigid and accurate support of the indenter on three axes and space under the workpiece for the future addition of a second indenter. The path of the indenter is numerically controlled via a PCI board motion controller.

Applications

Potential applications include:

• manufacture or repair of automotive parts
• custom-made medical braces such as ankle supports and dental plates
• bespoke architectural features and signage
• casing for machines and electrical goods

Current research

Research projects currently underway include:

• development of a model for tool force prediction with experimental verification
• investigation of the through-thickness deformation of the sheet and factors affecting it
• investigation of the factors influencing forming limits
• investigation of the applicability of ISF to a range of sandwich panel materials

Collaborators

We are working in collaboration with Dr Stephen Duncan and Ankor Raithatha at University of Oxford Control Group to develop real-time process control of incremental sheet forming.

Publications

• Allwood, J.M., et al., A novel method for the rapid production of inexpensive dies and moulds with surfaces made by incremental sheet forming. Proc. Instn Mech. Engrs, Part B, J. Engineering Manufacture, 2005. 220.
• Allwood, J.M., N.E. Houghton, and K.P. Jackson. The design of an incremental sheet forming machine. in SheMet '05 International Conference on Sheet Metal. 2005. Erlangen, Germany.
• Allwood, J.M., G.P.F. King, and J. Duflou, A structured search for applications of the incremental sheet forming process by product segmentation. Proc I Mech E Part B J Eng Manuf, 2005. 219(2): p. 239-244.
• Allwood, J.M. and H. Utsunomiya, A survey of flexible forming processes in Japan. International Journal of Machine Tools & Manufacture, 2006. 46(15): p. 1939-1960.
• Allwood, J.M., D.R. Shouler, and A.E. Tekkaya. The increased forming limits of incremental sheet forming processes. in SheMet '07 International Conference on Sheet Metal. 2007. Palermo, Italy.
• Jackson, K.P. and J.M. Allwood. Incremental Sheet Forming Research at Cambridge University. in Proceedings of the 4th JSTP International Seminar on Precision Forging. 2006. Nara, Japan.
• Jackson, K.P., J. Allwood, and M. Landert. Incremental Forming of Sandwich Panels. in SheMet'07 International Conference on Sheet Metal. 2007. Palermo, Sicily.
• A. Raithatha, S. Duncan, K. Jackson and J. Allwood, Second order cone programming in modeling incremental deformation, Proc. 26th American Control Conference, New York, 2007.
• A. Raithatha, K. Jackson, S. Duncan and J. Allwood, New method for modelling deformation in incremental sheet forming, Proc. IEEE CCA, Munich, 2006.