LATERAL COMPRESSION OF A SQUARE OR RECTANGULAR TUBE BETWEEN 2 PARALLEL NARROW WIDTH INDENTERS PLACED NON-ORTHOGONALLY

Collapse behavior of aluminum tubes of square and rectangular cross-sections, when compressed between two identical narrow width indenters placed symmetrically in parallel alignment, is examined. Experiments were performed wherein the angle between the axes of tube and indenters was varied from 0-degree to 90-degrees. Load-compression curves and deformation histories of typical specimens are presented. The collapse of the tubes was seen to be generally symmetrical, though asymmetries were observed in some tubes. Considering only the symmetrical mode of deformation, an analysis is presented for constructing the load-compression curves as well as the shape of the deforming tube. The analysis considers the energy absorbed in stationary and rolling plastic hinges which are formed in the collapsing tube. Computed results thus obtained compare well with the experiments.