Split-Hopkinson pressure bar

Although there are various setups and techniques currently in use for the split-Hopkinson pressure bar, the underlying principles for the test and measurement are the same.

Assuming deformation in the specimen is uniform, the stress and strain can be calculated from the amplitudes of the incident, transmitted, and reflected waves.

The specimen had a snug fit on the incident and transmission side in order to bypass an initial compression wave.

The compression wave would ideally pass through the composite collar and then reflect off the free end in tension.

[9] As with tension testing, there exist a variety of methods for specimen attachment and loading when subjecting materials to torsion on a SHPB.

This method is particularly sensitive to error because each charge must apply an equal impulse to the incident bar (to create pure torsion without bending) and must both detonate simultaneously.

Explosive-loading is also unlikely to produce clean incident waves, which may cause uneven strain rates throughout the test.