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基于X射线计算机断层扫描技术,重构了能够反映闭孔泡沫铝真实细观结构的三维有限元模型。采用数值模拟与试验测试相结合的方法,研究了泡沫铝在准静态单轴压缩载荷作用下的力学响应及其变形机制,重点关注了平台阶段及致密化阶段的变形模式。结果表明:试件中变形带的出现是压缩过程进入平台阶段的一个标志,此时棱杆和孔壁的变形以塑性弯曲为主;平台阶段,棱杆及孔壁的变形逐渐向塑性起皱与塑性屈曲转变;伴随致密化阶段的发生,变形带内部的胞孔严重坍塌,呈‘双凹圆盘’状。闭孔泡沫铝细观结构变形模式的数值模拟与试验结果相符,验证了该模型的有效性,为进一步研究各相关物理量(相对密度、加载速率等)及变形机制对其宏观吸能性能的影响奠定了基础。
Based on X-ray computed tomography, a three-dimensional finite element model that reflects the true mesostructure of closed-cell aluminum foam is reconstructed. The mechanical response and deformation mechanism of aluminum foam under quasi-static uniaxial compressive load are investigated by means of numerical simulation and test. The deformation modes of the stage and densification stage are focused on. The results show that the appearance of the deformation zone in the specimen is a sign that the compression process enters the stage of the platform. At this time, the deformation of the edge bars and the hole wall is dominated by plastic bending. At the stage of the stage, And plastic buckling changes. With the densification stage occurring, the cells inside the deformation zone collapsed seriously, showing a shape of “biconcave disk.” The numerical simulation of the closed-cell aluminum foam deformation mode is consistent with the experimental results, and the validity of the model is verified. In order to further study the influence of the relative physical quantities (relative density, loading rate, etc.) and deformation mechanism on the macroscopic energy absorption Foundation.