On development of urgent repair techniques for steel pipe destroyed by natural disaster (I). Explosive welding test and optical measurement of flyer motion

The experimental study on the application of explosive welding technique to urgent repairs of gas and water pipe networks was conducted. The relationship between the damage to the pipe and experimental parameters such as stand off distance and amount of explosive has been determined by a series of the explosive welding tests. The deflection of the pipe is maximum without stand-off under the same amount of emulsion explosive. As stand-off increases, the deflection of the pipe is decreased. To the definite amount of explosive, when stand-off is more than 5 mm, the deflection of the pipe becomes approximately constant. Moreover, the motion of the flyer was investigated by optical experiments. Regardless of the amount of explosive, the velocity of the flyer plate is accelerated instantly over 200 m/s within 0.5 mm flying distance and reached approximately constant velocity at short flying distance smaller than 5 mm.