Innovative impact testing machine for enhancing impact related research in Australia

Abstract

This paper summarises the development of a state-of-art impact testing machine for simulating impacts such as vehicular crashes or debris impacts onto structures. The machine has a 200 kg pneumatically powered projectile which can travel horizontally within the barrel of the machine with a maximum velocity of 50 m/s to impact the target structure. The maximum kinetic energy that can be generated by the projectile is 125 kJ by using different combinations of mass and velocity. The diameter of the projectile is 214 mm, and its impacting face can be changed to different shapes, such as flat circle, flat square or an elliptical nose to suit different impact scenarios. An innovative braking mechanism incorporating a crush tube is attached within the barrel to ensure safety when the projectile fails to be restrained by the impact. The crush tube can absorb the maximum imparted by the moving projectile. An advanced data acquisition system is installed to collect quantitative and qualitative test data during a period of 50 ms to 1 s. Two high-speed digital image correlation (DIC) cameras are attached and synchronised with the operation of the impact testing machine to record the images at the rate of 50,000 frames per second. Outputs in terms of strains, deformations, accelerations of the target structure with a record of damage history can be analysed using this 3D DIC technique. The paper also briefly presents the first application of this machine for impact testing masonry wall structures.