闭孔泡沫铝压缩力学性能的实验和三维有限元模拟

Based on X-ray electronic computed tomography technology, a three-dimensional finite element model was established to reflect the true structure of closed-cell aluminum foam. Firstly, the quasi-static and dynamic compressive mechanical properties of closed-cell aluminum foam were analyzed based on experiments and numerical simulations. Then the deformation characteristics and mechanical properties of closed-cell aluminum foam were analyzed. Finally, the reliability of the model was verified. The results show that a long platform stage appears on the stress-strain curve of closed-cell aluminum foam under quasi-static and dynamic loading. Under quasi-static compression, the specimens exhibit local plastic deformation mainly along the loading axis at 45°. At low compression rate, the deformation mode is the same as under quasi-static compression, stress concentration occurs first in the structural weakness of the closed-cell aluminum foam specimen, until material plasticity bend. Under high-speed compression, the loading end of the specimen first reaches the yield stress. Comparing the yield strength at different strain rates, the yield strength of closed-cell aluminum foam under dynamic compression is higher than that of quasi-static compression. When the strain rate of closed-cell aluminum foam specimen is 280~700 s^-1, the change of yield strength is not obvious. The strain rate increases to 2 000 s^-1, and the yield strength increases slightly.