Strain rate dependent compression response of Ni-foam investigated by experimental and FEM simulation methods

Metal foams can be used as structural materials for impact energy absorption applications, due to the extended plateau stress they exert under compressive loads. The compressive behaviour of Ni-foams was studied by experimental and computational methods at various strain rates. The geometry of the porous material was reconstructed based on X-ray computed tomography measurements and used in a FEM simulation software package, facilitating large unconstrained plastic deformation, to determine its response under variable strain rates. SEM in situ compression tests were employed to measure the load–displacement response of the foam, while allowing the acquisition of images illustrating the deformed metal foam struts. The results of the study indicated that the introduced FEM model provides reliable insight with regard to the response of metal foams under various compressive strain rates. Additionally, the FEM model facilitates a holistic overview of the deformation phenomena occurring within the porous structure on both macro- and micro-scales.

Research highlights
► The compression response of Ni-foam was computationally and experimentally examined.
► X-ray computer tomography was employed for capturing the exact foam geometry.
► The effect of strain rate on the response of Ni-foam was registered by the FEM model.
► The FEM model allows for explaining the foam deformation and buckling phenomena.
► SEM in situ compression tests enabled the visualization of the deformed struts.