Strain in Shear, and Material Behaviour in Incremental Forming


Article Preview

This paper discusses some consequences of forming by shear, a situation that is sometimes claimed to occur in incremental forming. The determination of the principal strains and principal directions is discussed in detail. Two methods are presented: using a circular grid (although simulated on the computer), and by deriving formulae from the theory; both yield identical results. The strains assuming forming by shear are found to be (much) higher than in situations of forming by stretch. This affects notably more fundamental studies on material behaviour in incremental forming. The effects are illustrated using experimental data obtained with pre-stressed material.



Main Theme:

Edited by:

F. Micari, M. Geiger, J. Duflou, B. Shirvani, R. Clarke, R. Di Lorenzo and L. Fratini




W. C. Emmens and A.H. van den Boogaard, "Strain in Shear, and Material Behaviour in Incremental Forming", Key Engineering Materials, Vol. 344, pp. 519-526, 2007

Online since:

July 2007




[1] J. Jeswiet. Asymmetric Incremental Sheet Forming. Proceedings 11th Shemet, Apr 05-08, 2005, Erlangen, Germany, pp.35-58.

[2] T.J. Kim, D.Y. Yang. Improvement of formability for the incremental sheet metal forming process. Int. Journal of Mechanical Sciences 42 (2000) 1271-1286.


[3] L.E. Malvern; Introduction to the mechanics of a continuous medium; Prentice-Hall Inc. Englewood Cliffs, New Jersey, (1969).

[4] A.H. van den Boogaard; Thermally Enhanced Forming of Aluminium Sheet; Thesis University of Twente, the Netherlands, (2002).

[5] E. Hagan, J. Jeswiet. Effect of wall angle on Al 3003 strain hardening for parts formed by computer numerical control incremental forming. Proc. Inst. Mech. Engnrs vol 217(2003), Part B: J. Engineering Manufacture, pp.1571-1579.