The Plastic Buckling of Thin-Walled Tubes Subject to Magnetomotive Forces

Abstract

Aluminium alloy tubes and rings can be reduced in diameter by means of external coils through which a large capacitor bank is discharged, due to the high radial transient magnetic pressure. Both the radial and perturbed motions are investigated theoretically and experimentally. Predictions of the current waveform, radial displacement and the number of wrinkles on the tube agree well with the experimental results. The number of wrinkles increases with tube length and diameter. However, geometrically similar tubes, when reduced to the same final hoop strain, have similar buckled shapes with the same number of wrinkles.