Instrumented Charpy impact test / Syamsul El-Adha and Haidil Mustafa

Impact testing is today a common laboratory practice for evaluating the impact performance of plastics. Although tests have been standardized for many years they represent now almost as much mystery as in Charpy's or lzod's time, at the beginning of the present century. The first and most important questions are :- What kind of correlation exists between the measured parameter (usually the energy) and the actual behaviour of the materials? - Does any method exist, within those standardized by various organizations, which gives us the chance to classify the materials according to actual behaviour? The answers to these questions are not very simple because behind them there is the whole field of the science of strength of materials in which to find the answers. During the last ten years remarkable steps towards a better comprehension of impact test phenomenology have been made. New equipment and 'theoretical models have been proposed, in particular in accordance with fracture mechanics theory. This review intends to give a picture of what has happened in the field of impact testing of plastics in this period, pointing out the main results achieved.