抄録
In the free expansion of a tube end by electromagnetic force, the effects of forming conditions on the deformed shape are experimentally investigated. The charged energy of condenser bank, the electrical properties of the coil protecter and geometries such as the relative position of a tube end to the coil, and the tube length, are taken as experimental parameters. In most cases, forming operation results in a type of flaring, and in the case of a combination of short tube and high charged energy it results in flanging. Results for flaring are summarized as follows : (1) The radial expansion rate, defined as conventional hoop strain varies in proportion to the charged energy. (2) The end effect of the solenoidal coil vanishes around a point distant from the coil end by a half of the tube radius. (3) Local expansion rate at the tube end increases with lower electrical conductivity of the coil protecter. (4) Deformed shapes near the fixed end and central part, like a plateau, do not depend on any parameter except for the charged energy. A longer tube merely increases the width of the central plateau.
