Impact resistance of mild steel pipes: an experimental study

This report describes the results of 43 impact tests on 152 mm (6 in) nominal bore steel pipes. The missiles included solid steel billets and sections of steel pipe with impact velocities in the range 46 to 325 ms-1. The tests showed that, for the solid billets, the impact resistances of the pipes were greater than expected from previous tests on flat plates. The perforation energies have been correlated against normalised target wall thickness and relative diameter of missile and target. The results of non-circular section missiles can be predicted using an equivalent circular missile based on the length of the perimeter. The correlation provides satisfactory indications of the results obtained with axially-impacting pipe sections with outer diameters equal to the target pipe diameter. Laterally-impacting pipe missiles were unable to cause perforation of the target or initiate fracture in the target pipe wall even when the target-pipe section collapsed completely. However, these tests indicated that the global response of the impacted pipe could transmit very large forces to the supporting structure. (author)