Int.J.Mech.Sci. 42, 1887-1910, 2000
F.D. Fischer¹, F.G. Rammerstorfer² N. Friedl² and W. Wieser¹
¹Institute of Mechanics,
University of Mining and Metallurgy, Leoben, Austria
²Institute of Lightweight Structures and Aerospace Engineering,
TU Wien, Vienna, Austria
The paper deals with analytical and numerical considerations of buckling
phenomena in thin plates or strips under in-plane loads which typically
appear during rolling and levelling, i.e. straightening bye stretching,
of sheet metal.
Buckling due to self-equilibrating residual stresses, caused by the rolling
process, in eventual conjunction with global tensile stresses (denoted as
"rolling buckling") as well as buckling during the levelling process (denoted
as "stretching buckling" or "towel buckling") are considered.
Analytical estimates are derived and compared against results of numerical
simulations and field observations.
Mode jumping by varying the global strip tension is explained on the basis of
the derived analytical solutions.
It is shown how from the waves, i.e. height and length, observed on the strip
sliding over or lying on a rigid plane one can provide information about
the distribution of the differences in the plastic strains over the width
of the strip which lead to the buckled configuration.
And, vice versa, knowledge of the plastic strain distribution can be used for
estimating the expected wave heights representing a measure for the
geometrical quality of the rolled product.
The influence of the dead weight of the strip on the post-buckling pattern
is also discussed on the basis of non-linear analyses.