铝合金薄壁圆管动态膨胀剪切断裂的实验研究

Dynamic fragmentation of expanding aluminum alloy cylinder shell

采用电磁驱动金属圆管膨胀技术对6063薄壁铝合金圆管的动态膨胀断裂过程进行实验研究,圆管膨胀速度可达140~200 m/s,应变率为4 500~6 500 s-1,并对剪切局域化形成过程、应变率影响及试样温升等进行讨论。结果表明：铝合金薄壁圆管动态断裂经历了均匀膨胀、剪切局域化变形及裂纹沿剪切局域化带发展过程,剪切局域化变形带与圆管径向呈45°或135°的分布。分析表明：碎片特征尺寸随加载率提高而减小,断裂应变随着加载率提高而增大。

The electromagnetical loading technique was adopted for studing the behavior of dynamic expansion of 6063 aluminum alloy tube, in which the expanding velocity is in the range froml40 to 200 m/s, and corresponding to strain rate from 4 500 s-1 to 6 500 s-1. The results show that the uniform deformation, shear localization and fracture along the localization band occur in expanding tube in succession, and shear localization band is at an angle of 45° or 135° to the axial direction of shell approximately. The characteristics of fragment size decreases with increasing strain rate, and correspondingly, the fracture strain increases with increasing strain rate.