Mechanical properties of foam aluminum with different sizes

The density uniformity and the corresponding size effect were analyzed for two different foam aluminum materials.Analyzed results show that the more non-uniform the density distribution of the foam aluminum,the more significant the size effect.But if the density distribution interval is smaller and in line with normal distribution,the size effect is weaker.Based on the assumption of the stress uniformity in the split Hopkinson pressure bar tests,the quartz pieces were used to measure the time required by the stress uniformity process at the two ends of the specimens.It is found that the larger the axial size of the foam specimen,the more evident the influence of the inertial effect.And the right axial sizes were chosen to decouple the inertial effect of the specimen(wave effect) from the strain rate effect.The experimental results display that the foam materials have obvious strain rate effects.