Impact Dynamics is concerned with the study of collisions, whether they be from dropping a mobile phone onto a hard surface, crashing a car into a brick wall, a bullet striking an armour plate or even a meteorite crashing to earth.
The Impact Dynamics Research Group investigates how materials and structures behave under dynamic loading conditions. We are able to test materials over a wide spectrum of strain rates ranging from 10-3 to 107 s-1. An advanced array of loading methods, visualisation techniques and data-capturing diagnostics are available for full material characterization.
The Two-Stage Light-Gas Gun
Our flagship piece of equipment is also one of our most versatile, boasting three different firing configurations to suit the needs of most any high-velocity impact experiment. Two single-stage configurations have barrel bore diameters of 22 and 70 mm to accommodate varying projectile sizes over a velocity range of 150 to 1,100 m/s. These velocities are capable of imparting high pressure shock waves into targets. Plate impact studies can be conducted under high vacuum with the addition of a secondary chamber at the exit of the gun barrel within the primary target ch
When configured for two-stage experiments the gun is capable of firing a 22 mm diameter projectile to a velocity of 4.5 km/s making it the fastest gun in the Southern Hemisphere! At these extreme pressures the projectile and/or target can actually vaporize on impact! Having the capability to replicate pressures approaching those seen within the centres of planetary bodies provides a unique opportunity for novel, cutting edge scientific experiments.
We are also able to test how materials behave under dynamic compression and tension using our Split-Hopkinson-Pressure-Bar (SHPB) system. This equipment enables us to evaluate the performance of materials subjected to loading conditions that are similar to a bullet striking a plate of armour, for example. Dynamic stress strain data generated from this testing is of paramount importance for providing material behaviour data required for computational models.
Instrumented Drop Tower
For lower loading rate applications we have an instrumented drop tower (Instron CEAST 9350) that is capable of dropping a 6.25 kg mass at 24 m/s equating to an impact energy of 1800 J. Equivalently, this is like dropping a 6.25 kg mass from a height of 29.4 m. Drop tower testing allows us to replicate the types of strain rates experienced during car crashes, bicycle accidents, and sports collisions. The instrumented tup allows us to record the force, impulse and energy-transfer history during the impact event.
To supplement our experimental efforts, the Impact Dynamics Research Group is also active in computational modelling using commercial explicit codes such as ABAQUS, LS-DYNA and ANSYS® AUTODYN. These programs help elucidate the physics of interactions between impacted materials.
Current Research Projects