aluminium & mild steel; Typical load-compression; and deformed shapes of the collapsed; tubes are presented.
Different size tubes of aluminium and mild steel were subjected to axial
compression in an Instron machine. The tubes chosen were such that they
collapsed in aM-symmetric concertina mode. Typical load-compression
curves and deformed shapes of the collapsed tubes are presented. These
reveal that the axi-symmetric folds formed in the deforming specimens
extend both inside and outside of the line of original tube radius, and the
ratio of the inside to outside fold lengths depends on the tube dimensions.
Considering the tube collapse mechanism as observed experimentally, an
analysis is presented in an attempt to predict the mean collapse load and the
post collapse load-compression curve. The computed values of the mean
collapse load and the load-compression curve during a load oscillation, are
presented and compared with the experiments, as well as with some existing