闭孔泡沫铝准静态压剪性能研究

Mechanical Behaviors of Closed-Cell Aluminum Foams under Quasi-Static Compression-Shear Loads

通过添加斜端面垫块和长方体套筒,利用材料试验机对闭孔泡沫铝进行准静态下的压剪复合加载实验。改变斜端面垫块的角度,得到泡沫铝在不同压剪加载路径下的力学性能。对试样进行受力分析,得到泡沫铝在压剪空间的屈服面。同时采用有限元软件LS-DYNA对闭孔泡沫铝的压剪加载过程进行数值模拟,仿真屈服面与实验屈服面吻合较好。仿真研究表明,密度相同的泡沫铝,在一定孔径范围内,胞孔尺寸越大,屈服应力越大,泡沫铝的承载能力越好。

In the present work,we conducted the quasi-static compression-shear experiments on the closed-cell aluminum foams using an improved testing machine and installing beveled bars and a column sleeve.By changing the angle of the inclined beveled bars we obtained the mechanical properties of the aluminum foams in different compression-shear loading paths,and then figured out the aluminum foam’s experiment yield surface from the force analysis of the specimen used.At the same time,we simulated the compression-shear process of the closed-cell aluminum foams using the finite element software LS-DYNA.The simulated yield surface is in good agreement with the experimental yield surface.The results show that,for the aluminum foams of the same density and in a given range of the cell size,the yield strength of the closed-cell aluminum foams increases with the increase of the cell size,and so does its load capacity.