Search

Entangled porous metallic wire material (EPMWM) has the potential as a thermal insulation material in defence and engineering. In order to optimize its thermophysical properties at the design stage, it is of great significance to reveal the thermal response mechanism of EPMWM based on its complex structural effects. In the present work, virtual manufacturing technology (VMT) was developed to restore the physics-based 3D model of EPMWM. On this basis, the transient thermal analysis is carried out to explore the contact-relevant thermal behavior of EPMWM, and then the spiral unit containing unique structural information are further extracted and counted. In particular, the thermal resistance network is numerically constructed based on the spiral unit through the thermoelectric analogy method to accurately predict the effective thermal conductivity (ETC) of EPMWM. Finally, the thermal diffusivity and specific heat of the samples were obtained by the laser thermal analyzer to calculate the ETC and thermal insulation factor of interest. The results show that the ETC of EPMWM increases with increasing temperature or reducing density under the experimental conditions. The numerical prediction is consistent with the experimental result and the average error is less than 4%.

Composite materials exhibit the impressive mechanical properties of high damping and stiffness, which cannot be attained by employing conventional single materials. Along these lines, a novel material architecture is presented in this work in order to fabricate composites with enhanced mechanical characteristics. More specifically, entangled metallic wire materials were used as the active matrix, whereas polyurethane was employed as the reinforcement elements. As a result, an entangled metallic wire material-polyurethane composite with high damping and stiffness was prepared by enforcing the vacuum infiltration method. On top of that, the mechanical properties (loss factor, energy consumption, and average stiffness) of the proposed composite materials were characterized by performing dynamic tests, and its fatigue characteristics were verified by the micro-interface bonding, as well as the macro-damage factor. The impact of the density, preloading spacing, loading amplitude, and exciting frequency on the mechanical properties of the composites were also thoroughly analyzed. The extracted results indicate that the mechanical properties of the composites were significantly enhanced than those of the pure materials due to the introduction of interface friction. Moreover, the average stiffness of the composites was about 10 times the respective value of the entangled metallic wire material. Interestingly, a rise in the loading period leads to some failure between the composite interfaces, which reduces the stiffness property but enhances the damping dissipation properties. Finally, a comprehensive dynamic mechanical model of the composites was established, while it was experimentally verified. The proposed composites possess higher damping features, i.e., stiffness characteristics, and maintain better fatigue characteristics, which can broaden the application range of the composites. In addition, we provide a theoretical and experimental framework for the research and applications in the field of metal matrix composites.