THE USE OF THE SPLIT HOPKINSON PRESSURE BAR TECHNIQUES IN HIGH-STRAINRATE MATERIALS TESTING

The use of the split Hopkinson pressure bar (SHPB) techniques for mate rials testing under a high rate of loading is described, including var ious modifications of the original compression testing set-up for tens ion testing, torsion testing and dynamic fracture testing. Details of measurement techniques and instrumentation are included together with the calibration of the air gun and strain wave measuring system. The S HPB techniques provide a relatively cheap and simple method for high s train rate materials testing with an acceptable level of accuracy when sufficient care is taken for the proper lubrication of the interfaces and the correct length-radius ratio of the specimen is chosen. The li mitations of the method are discussed and possible improvements using FFT (fast Fourier transform) techniques to take into account dispersio n effects are considered.