High strain rate behaviour of different types of chocolate

The mechanical behaviour of five different chocolate types (dark, extra dark, milk, white, and ruby) at high strain rates was studied. The experimental arrangement known as the Split Hopkinson Pressure Bar (SHPB) method was used. This experimental procedure enables to study the mechanical behaviour of materials at strain rates up to 103 1/s. The use of SHPB technique shows that the mechanical properties of tested chocolates significantly increase with the strain rate. This increase is much higher than that observed during the quasi static testing where the strain rate achieves values about 10-3 1/s.