A Double-Pulse Torsional Hopkinson-Bar Technique for Investigating Strain-Rate Effects.
Interim rept. Mar-Oct 72,
OXFORD UNIV (ENGLAND) DEPT OF ENGINEERING SCIENCE
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A brief description is given of an apparatus by means of which a torsional wave can be generated which exhibits a double-step structure. Each step has a rise time of order 40 microseconds, and the time between them is about 150 microseconds three different bar systems have been built, giving respectively 4.6, 6.5 and 10.0 as the nominal ratio of the amplitude of the second step to that of the first. By means of this apparatus, a short thin-walled tubular specimen can be subjected to a sudden change in strain rate at rates in the range 10 to 500 reciprocal second. The test method is described, and some preliminary results are presented and discussed in order to illustrate the potential and limitations of the technique. Author, modified-PL
- Metallurgy and Metallography
- Test Facilities, Equipment and Methods