Split-Hopkinson pressure bar (SHPB)
The new split-Hopkinson pressure bar at SIMLab consists of a high-pressure chamber unit that can accelerate a projectile against the end of the input bar. The diameter of the projectile and thus the input and output bars, which are made of steel, are in the range 16-32 mm. The length of the projectile is 1750 mm, giving a maximum pulse length of 70 ms. The high-pressure chamber has the capacity to accelerate a projectile with a diameter of 32 mm up to an impact velocity of 20 m/s.
The data acquisition of the new bar is the same as for the split-Hopkinson tension bar, i.e. the relative deformation of the compressed specimen as a function of time can be calculated from strain gauge measurements on the input and output bars and one-dimensional stress wave theory.