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采用球形压头对闭孔铝泡沫材料进行了准静态压痕实验,研究了不同直径、铝泡沫相对密度及边界条件对铝泡沫的压痕硬度、吸能能力及能量吸收率的影响。研究表明,铝泡沫在球形压头作用下的响应曲线可采用幂函数形式进行描述,幂函数指数随相对密度的增大而线性增加。铝泡沫压痕处的断面显示铝泡沫变形被严格限制在压头之下,铝泡沫的压痕变形是局部的不均匀变形。铝泡沫的压痕硬度及吸能能力均随压头直径的增大而线性减小,但它们却均随铝泡沫相对密度的增大而线性增大;能量吸收率不随压头直径和铝泡沫相对密度而变化。在一定压痕深度范围内,刚性基础和简支条件对铝泡沫的压痕响应影响可以忽略不计。最后基于实验数据分别建立了压痕硬度和吸能能力与压头直径及铝泡沫相对密度的关系。
A quasi-static indentation test was conducted on a closed-cell aluminum foam with a spherical indenter. The effects of different diameters, the relative density of the aluminum foam and the boundary conditions on the indentation hardness, energy absorption capacity and energy absorption rate of the aluminum foam were studied. The results show that the response curve of aluminum foam under the action of spherical pressure head can be described by power function, and the exponential of power function increases linearly with the increase of relative density. The cross section of the aluminum foam indentation shows that the deformation of the aluminum foam is strictly limited under the indenter, and the indentation deformation of the aluminum foam is locally non-uniform deformation. The indentation hardness and energy absorption capacity of aluminum foam decrease linearly with the increase of pressure head diameter, but they all increase linearly with the relative density of aluminum foam. The energy absorption rate does not vary with the diameter of head and aluminum foam Relative density and change. In a certain depth of indentation, the influence of rigid foundation and simple support on the indentation response of aluminum foam is negligible. Finally, based on the experimental data, the relationship between indentation hardness and energy absorption capacity, the diameter of the indenter and the relative density of aluminum foam was established respectively.