The Measurement of Impact Forces under Dynamic Crush using a Drop Tower Test Facility

The design of structural components requires a knowledge of their crush characteristics, particularly the load-carrying capacity during dynamic crash. Although many attempts have been made to develop analytical techniques or methods for predicting these characteristics, experimental tests are still needed to provide data for real structures for either development or validation.

This report describes an experimental method for determining the force-deflection characteristics during dynamic crush of square steel columns using a drop tower test facility. The custom-designed load cells were used for the measurements of the impact and the reaction forces at both ends of specimens, which were subjected to a 30 mph impact. Instrumentation for data acquisition and detailed data reduction for analysis are also presented. Dynamic force-deflection data are then verified through energy computations of the total kinetic energy of the system and the resulting energy absorbed by the specimens, which are calculated from measured impact forces and dynamic deflection.