Interpretation of signals from dropweight impact tests

A spring-mass model has been developed to describe the dropweight impact re sponse of CFRP panels. The model separates the effects of the main impact i mpulse, high frequency oscillations and free vibrations and can be used as a reliable guide for effective digital filtering of signals from dropweight impact tests. Whilst the model at present does not account for damage, the onset of high frequencies towards the peak impact force indicate the onset of damage in the panel. The oscillations become larger and extend over a w ider plateau as the perforation threshold energy is approached. (C) 1998 Pu blished by Elsevier Science Ltd. All rights reserved.