Specialized Impact Tester

Impact tests are performed to measure the response of a material to dynamic loading. Impact testing in the beverage can industry is used to develop new can designs, new can materials, and for quality assurance in production.

System Features

The beverage can impact test machine shown in the photograph above is designed for impact velocities up to 10 ft/s. A hemispherical striker is used to indent or puncture the can. The striker is instrumented with strain gages so that load, deflection, and energy data can be measured. An optical encoder is used to measure the velocity of the striker from release up to impact with the can. The system is capable of detecting can wall thickness variations on the order of 0.0001 inches (1 ten-thousandth of an inch). The test machine operates inside a polycarbonate enclosure to contain any fluid released from the can during testing and to protect the operator.

Example Data

Example data are shown below. The top graph shows the striker velocity measurement as a function of time from the release up to impact with the can. The velocity at impact is used in the integration of the instrument striker signal (see Instrumented Impact Testing page). The lower plot shows the measured voltage from the strain gages. These data are converted into load data through the calibration with a NIST traceable load cell. The most useful test parameters for characterizing can performance are peak load, deflection to peak load, and energy to peak load.

Specialized Impact Tester