Buckling of rolled strip

Abstract

When a strip of metal formed by cold rolling is examined, it is frequently found to contain buckles. If centre buckles occur, the strip is said to have a 'long centre' while edge buckles are usually attributed to 'long edges'. If the wavelength and amplitude of the buckles are large, the shape of the buckles will obviously depend on the configuration in which the strip is held. For example, we expect the pattern of buckles of a strip laid on a flat table to be different those of a strip suspended between two rollers and subjected to tension. It is observed in practice, however, that buckling occurs in some cases with a characteristic wavelength that is relatively robust to strip configuration.

An understanding of buckling patterns is of considerable interest to manufacturers of strip, particularly as current trends are to produce thinner sheet which is consequently more prone to buckling. The specific question that BHP Coated Products Division asked the Study Group to consider was whether long centres and edges could give rise to buckling patterns with a robust characteristic frequency.