Notched round copper bars are prestrained to various extents, recrystallize
d, and finally strained until fracture. Void nucleation and growth during p
restraining cause a decrease in the macroscopic void coalescence strain. Mo
delling of this experiment requires a proper account of the changes in void
sizes and their interdistances during prestraining. Modelling based on the
Gurson-Leblond-Perrin model for void growth and the Thomason model for voi
d coalescence is proposed. Comparison with experimental results allows a de
monstration of the validity of the Thomason model and the inadequacy of mod
els based on a critical porosity value. Porosity at coalescence is found to
depend on the initial void volume fraction, the how properties and the str
ess state.