低速冲击下泡沫金属填充薄壁圆管的弯曲行为

Bending behavior of thin-walled cylindrical tubes filled with metallic foam under low-velocity impact

采用实验方法研究了低速冲击下泡沫金属填充薄壁圆管的弯曲行为,详细说明了实验方法和原理。通过与准静态实验结果的比较发现,冲击加载使泡沫金属填充圆管跨中截面的局部压入变形增大,跨中截面高度变小,结构下缘拉裂破坏延迟。由于结构的惯性效应,锤头总冲击力高于准静态加载时的对应值。

Three-point dynamic bending tests and quasi-static tests were carried out,respectively.And the experimental methods and the corresponding experimental principle were introduced in details.In the experiments,aluminum alloy 6063T6 was chosen as the thin-walled tube material,the tubes with three different thicknesses of 1.0,1.5 and 1.8 mm had an identical outside diameter of 38 mm,and the aluminum-alloy foam with two different densities was used as filling cores.The experimental results display that under low-velocity impact,the thinner-walled tubes are prone to tensile damage at the lower edges of the middle sections;that due to the inertia effect,the punch forces under low-velocity impact are higher than those under quasi-static load.In addition,the local indentation by low-velocity impact is larger than that by quasi-static load,which makes the tensile failure of the lower edge of the structure delay.Hence,the bending stiffness of the middle sections under low-velocity impact significantly decreases and the ultimate displacement when the structures fracture increases.