56 Collapse oj Sho?<t Tubes by External Pressure. 



of the collapsing pressure tha7i the former. The numerical 

 value of the constant k for these experiments would appear 

 to be about .1/73, and the critical length L to vary from about 

 13 to 18 times the diameter ; but the tests cannot be regarded 

 as sufficient in number or covering a great enough range of 

 dimensions to confirm definitely the equation (3). 



Table I. — "Results of Tests on Solid drawn Steel Tubes 

 3 in. internal diameter, machined to various thicknesses. 



IVTp^n 





"Ratio 





Collapsing 



t 



Collapsing 



diameter 



(d) ins. 



Thickness 

 (t) ins. 



t 

 d 



Length 

 (I) ins. 



Pressure 



IK ^ • (^r 

 Ib.persq.m. v 



d 



rected) 



Pressure 



(corrected) 













Ib.per sq.in. 



3-038 



•0397 



•1131 



2-08 



1240 



0131 



1240 



3-037 



•0398 



•0131 



2-69 



1120 



0131 



1120 



3-034 



•0387 



•0128 



319 



1000 



0131 



1047 



3-038 



•0404 



•0133 



3-81 



1070 



0131 



1038 



3-018 



•0399 



•0132 



4-20 



1050 



0131 



1032 



3-035 



•0399 



•0132 



4-70 



880 



0131 



867 



3-017 



•0388 



•0129 



5-20 



840 



•0131 



865 



3 034 



•0404 



•0133 



5-68 



860 



0131 



834 



3-036 



•0396 



•0130 



6-71 



720 



0131 



730 



3-022 



•0420 



•0139 



7-77 



760 



0131 



674 



3-032 



•0407 



•0134 



8-70 



650 



0131 



620 



3-038 



•0390 



•0128 



9-70 



510 



0131 



534 



3038 



•0390 



•0128 



10-67 



480 



0131 



503 



3039 



•0407 



•0134 



11-68 



525 



0131 



502 



3-012 



•0347 



•0115 



12-71 



287 



0115 



287 



3-003 



•0310 



•0103 



11-72 



256 



0097 



228 



3-008 



•0333 



•0110 



11-70 



329 



0110 



329 



3-020 



•0342 



•0113 



11-70 



318 



0115 



345 



3-015 



•0358 



•0119 



11-70 



360 



0119 



360 



3037 



•0415 



•0137 



11-70 



510 



0137 



510 



3021 



•0449 



•0148 



11-70 



650 



0146 



630 



3-024 



•0483 



•0160 



11-70 



730 



0160 



730 



3-028 



•0487 



•0161 



11-70 



750 



0160 



745 



3027 



•0533 



•0176 



11-70 



965 



0176 



965 



3-031 



•0551 



•0182 



11-70 



1040 



0182 



1040 



3-032 



•0585 



•0193 



11-70 



1285 



0193 



1285 



3037 



•0625 



•0206 



11-70 



1345 



0206 



1345 



3020 



•0291 



•0096 



2-08 



695 



0097 



704 



3-025 



•0350 



•0116 



2-08 



1190 



0115 



1171 



3-035 



•0459 



•0152 



2-15 



1780 



0146 



1630 



3-040 



•0500 



•0164 



2-20 



2040 



0160 



1930 



3-020 



•0296 



•0098 



4-31 



510 



0097 



500 



3-020 



•0346 



•0114 



4-25 



795 



0115 



803 



3-030 



•0441 



•0145 



4-30 



1045 



0146 



1055 



3040 



0495 



•0163 



4-30 



1355 



0160 



1310 



3020 



•0294 



•0097 



6-67 



385 



0097 



380 



3030 



•0347 



•0115 



6-68 



520 



0115 



525 



3-030 



•0441 



•0145 



669 



880 



0146 



885 



3-040 



•0488 



•0160 



6-66 



1010 



0160 



1010 



