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摘要
Under impact, aluminum foam undergoes significant plastic deformation, and the kinetic energy of the impactor is dissipated in the process, thereby protecting the structure from damage. The failure modes of aluminum foam sandwich structures under impact are complex, involving plastic deformation, panel failure, and cracking of the bonding interface. Traditional numerical simulation methods are difficult to solve these discontinuous problems. Peridynamics is a non-local numerical method that describes the mechanical behavior of materials by solving spatial integral equations. It has unique advantages in solving crack propagation, material failure, progressive damage of composite materials, and multi-scale problems. Although the basic bond-based peridynamic theory cannot describe plasticity, the ordinary state-based peridynamic method decouples distortion and dilation and can easily simulate the plastic deformation of materials. Therefore, based on ordinary state-based peridynamics, the Mises yield criterion and the linear isotropic hardening model were introduced to study the factors affecting the impact resistance of aluminum foam sandwich structures. Two-dimensional mesoscopic models of aluminum foam sandwich structure were established by the Monte-Carlo method and impact was simulated using the peridynamic method. The influence of the porosity of aluminum foam on the impact resistance and damage mode of the sandwich structure was analyzed. The results show that the good plastic deformation ability of aluminum foam sandwich structure is the main factor for its buffering and protection, and within a certain range, the higher the porosity of aluminum foam core, the better impact resistance of the sandwich structure. When the porosity of aluminum foam increases from 0.4 to 0.7, the kinetic energy absorption rate of aluminum foam to the impactor increases from 90% to 99%. The simulation results are in good agreement with the experimental results, which verifies the accuracy of the simulation results and the effectiveness of the analysis conclusions. The numerical simulation predicts the crack propagation morphology of the plexiglass backplate, and the results show that improving the porosity of aluminum foam can obtain a better protection effect. ? 2023 Explosion and Shock Waves.
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