Deformation and failure behaviour of open cell Al foams under quasistatic and impact loading

The deformation behaviour and the mechanical properties of the quasistatically and the dynamically tested specimens are very similar. Higher strain rates result in a more homogeneously distributed deformation, however with a negligible influence on the plateau stress, densification strain and energy absorption characteristics. The highly efficient energy absorption during the plateau phase is due to microstructural mechanisms such as plastic bending of struts (mostly C- and S-curved) and different types of crack formation and growth in the struts. Local differences of the strut microstructure cause locally different mechanical behaviour of struts: while high plastic deformation leads to a more homogeneous macroscopic deformation, we assume brittle fracture of single struts promotes the formation of deformation bands.