Tensile Impact Testing by a Magnetic Loading Technique

Abstract

The techniques that have been employed in the construction of tension testing machines for use at impact rates of strain are summarized. The difficulties involved are briefly reviewed. The practicability of applying magnetic forces to the generation of dynamic loads is discussed and a new type of tensile impact machine, in which such forces are used, is then described. It is shown that with this machine, small specimens may be yielded in times as short as 5 μs and at strain rates of 1000 per second and above. Reliable stress–strain curves are presented for both ferrous and non-ferrous materials at various test temperatures and comparison is made with results obtained at conventional strain rates.