Development of an autographic falling-weight impact system



The objective of this project was to develop a system that would allow the determination of the energy absorbed during fracture in a falling-weight impact test. Equipment was developed which would allow the force exerted by the impact tup on the specimen to be determined during the test. Using this information and the equations developed, it was possible to convert force-versus-time traces on an oscilloscope to energy absorbed. Tests were conducted to compare the autographic method with the normal falling-weight method. The system was shown to give results which are similar to results from normal falling-weight impact tests, but requires much fewer specimens. Tests can be made and results can be obtained on small sample sizes, since results are obtained for each specimen tested. Also, a more representative value of falling-weight impact strength can be determined in cases where there are mixed failure modes. The autographic system may be used in those instances where there are limitations of material, and with further use it may eventually replace the normal falling-weight impact determination.