“…Thus, uniaxial compression tests are first conducted on cubic sample with the dimension of 40mm in three mutually perpendicular principal directions (shown in Figure 2) in order to characterize directional properties of this foam, which should be taken into consideration before investigating mechanical behavior. On the other hands, it is well-known that mechanical behavior of metallic foam is strongly sensitive to the ratio of the sample size to the cell size at length scales where the two are of the same order of magnitude (Bastawros et al, 2000;Onck et al, 2001;Andrews et al, 2001;Jeon and Asahina, 2005;Joseph et al, 2005;Rakow and Waas,2005;Tekoğlu and Onck, 2008;Caner and Bazant, 2009;Jeon et al, 2009;Tekoğlu et al, 2011;Su et al, 2014). Most researchers have adopted big size samples in the mechanical tests to avoid the size effect of cellular materials (McCullough et al, 1999;Ruan et al, 2002;Saha et al, 2005;Amsterdam et al, 2008;Lu et al, 2008;Shen et al, 2010;Mangipudi and Onck, 2011;Luong et al, 2013;Jin et al, 2015).…”