Torsional hopkinson bars testing - modification of adapters

Abstract

The Torsional Split Hopkinson Bar (TSHB) setup makes use of a pair of adapters to connect the specimen to the torsion bars. Currently, specimens are joined to the adapters with glue. However, there are many disadvantages in such a design. These disadvantages will be discussed in the report. One such example is that there is a high wastage of materials as the adapter could not be reuse. A new design is developed in this project. The design connects the adapters to the specimen by inserting pins mounted on the adapters into the specimen‟s flanges. The 1st prototype fabricated contains some designing flaws as there are difficulties in fitting the specimen to the adapters. The design is modified to correct these problems and a 2nd design is produced. Investigations were carried out to justify the use of this new design. The oscilloscope traces, strain rate against time plots and shear strain against shear strain plots of identical tests were carried out separately using the old glued design and the new pinned design. When compared, the results produced using the pinned adapters are similar to the results produced using the glued adapters. In conclusion, as the comparison shown, the new design is justified as the newly designed pinned adapter is capable of replacing the old glued adapter. Furthermore, the new design will resolve the many disadvantages of the old design.