The objective of this paper is the analysis of large planar and biaxial bending rotation response of thin-walled beams with square cross-section filled partially or fully with aluminium foam. The beams were subjected to the cantilever bending, and the characteristics of moment-rotation response were investigated varying the length of foam-filling, the orientation angle, and the adhesive strength. A general purpose nonlinear FE code Pam-Crash was used to generate results. It was shown that the aluminium foam filler retards inward sectional collapse of thin-walled column so that the multiple folds are formed increasing the bending resistance considerably. The initial and subsequent shrinking of failure locus were constructed, and the normality rule was checked for the partially or fully foam-filled columns in biaxial bending collapse.