PLASTIC FAILURE OF CYLINDRICAL SHELLS. 



625 



11 



outer ellipse ultimately developed into a hexagonal figure as shown in 

 Fig. 13 and at (a) in Fig. 15 (facing p. 5). 



The same tin was then turned in the sand bed and another test made, 

 away from the seam. The test figures are shown in Fig. 16 (Tin 1, Test B) 

 and failure occurred by the development of a circumferential split at the 

 centre of the cylinder on the minor axis of the smaller ellipse ; that split 

 was significant in the light of results to be described later. After the test 



Fig. 17. 



ram displacement , inches 



Load-Displacement Curves fob Milk 

 Tins with Imperfectly Reinforced Ends. 



an elliptical dent was found on the previously undamaged under-side of 

 the specimen, opposite to the loading point and is shown on the right of 

 (a) in Fig. 15 ; the split was on the far side of the cylinder. A check test 

 was made on the second of the stiffened cylinders ; the results were 

 similar and are shown in Fig. 16 (Tin 2) and at (b) in Fig. 15 (facing p. 5). 



The two remaining reinforced cylinders were deliberately made badly 

 to allow some, but not complete, freedom at the ends. 



In one, the specimen eventually split in spite of crumpling along the 

 minor axis of the dent as shown at (c) in Fig. 15 ; in the other the flexibility 



