The application of ultrasonics in metal forming applications has been shown to reduce the forming load significantly in many research
studies. The load reduction has been related to the stress superposition effect, rise in temperature and change in the friction condition
between the specimen and die interfaces. This paper reports an investigation into the effects of superimposed ultrasonic oscillation of
the die in compression tests on aluminium specimens. In particular, a finite element model is developed to simulate uniaxial compression
and to model the effects of a change in the friction boundary condition when ultrasonic excitation is applied to the lower platen. The
model predictions of the stress–strain relationship can be compared with test data to provide some insights into the effects of the interfacial
condition. The paper shows how the analysis of the test data, combined with finite element models of ultrasonic compression test
simulations, allows some initial conclusions to be drawn regarding the influence of the interfacial friction during ultrasonic compression.
2006 Elsevier B.V. All rights reserved.