3D reinforcement synergistic effect of embedded nickel-foam skeleton of polyurethane based on x-ray CT images: Experimental and finite element analysis

Monotonic shear tests were performed on Nickel Foam (NF)/Polyurethane (PU) and the results indicated that NF/PU was much greater than the sum of the individual phases in terms of strength and stiffness. Cyclic shear tests were carried out and it was found that shear evolution processes and failure modes of the composite were completely different from the individual phases and the damping properties were greatly improved. Revealing the synergistic mechanism of the 3D continuous metal skeleton on the PU is the key issue to explain the above phenomena. The geometric topology of NF was reproduced using CT technology and a fine-scale finite element model was established. The mechanical behavior between NF and PU was investigated at the meso-mechanical scale. The results show that the NF skeleton significantly improves the strength and damping properties of the PU. During cyclic shear, the effects of displacement and temperature on the mechanical and damping properties of the PU are significant. In comparison, the NF skeleton reduces the temperature sensitivity. Based on the analysis of experimental and FEA results, the monotonic and cyclic constitutive models of NF/PU were established. The shear constitutive model under the new loading/unloading criterion has good fitting accuracy and high reliability.