高速度衝撃による金属の変形と破壊(1)
1956 年 25 巻 3 号 p. 105-107
詳細
1956 年 25 巻 3 号 p. 105-107
Studies on deformation of Al and mild steel plates pierced by a bullet of 12.2φ×25mm with velocities of 230_??_490m/sec are given.
In the case of Al plates, the pierced hole is characterized by shear fracture. The de-lormation is the smaller, the larger the velocity of the bullet for a given thickness of the plate and the thinner the plate for a given velocity. The time repuired for piercing seems to affect the magnitude of deformation. Annealed plates show larger deformations when compared with as-rolled plates.
In the case of mild steel plates, there are two patterns; one is the clean shear fracture and the other the shear fracture accompanied with tensile fracture. The deformation is the smaller, the larger the velocity for the same pattern of the fracture. Annealing seems to make the deformation slightly larger.
In the case of eutectoid steel plates, in spite of the considerable deformability by slow punching, no plastic deformation is observed and brittle-type fracture appears on the back of the plate.
