630 



16 



PIPPARD AND CHITTY ON EXPERIMENTS ON THE 



that failure will start by the development of multiple lobing but that the 

 bending of the ends subsequently will cause the lobes to merge into a 

 single dent showing the boundary between the initial lobes as a ridge. 

 That efifect is shown at (c) in Fig. 19, and later evidence obtained from 

 explosive experiments clearly indicates that it does occur. 



Tests on Large Cylinders. 



As stated in the beginning of this Paper, the original object of the 

 investigation was to determine the behaviour of the cylinders shown in 

 Figs 4. The work originally contemplated, however, was extended on 

 account of the results obtained from the small cylindrical tins which have 

 been described in preceding pages. One result of those small-scale tests 

 was to emphasize the importance of the stiffness of the ends and a few 

 cylinders were therefore made with very stiff end disks connected by steel 



Table II. — Schedule of Tests on Large CyLLNDEES. 



rods as shown in Figs 6. Some of those, as well as some of the original 

 design, were used for tests under explosive loads, but one of them was 

 tested statically in the way described earlier. 



Table II is a schedule of the cylinders tested as described in this 

 Paper ; each one was given a reference number and when it was possible 

 to make two tests on one cylinder they are distinguished by letters after 

 the number. 



The method of testing has already been described. Before the cylinders 

 were embedded in the sand, lines dividing the surface into 1-inch squares 

 were carefully scribed upon them. Those lines served as a reference grid 

 for plotting contours of the dents obtained. The contours were actually 



