"> -80,000 

















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'f' 







PROPORTIONAL LIMIT / i 



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\ 7 / 











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4P00 - 8,000 - 12,000 



STRAIN, fllN./IN. 



Figure 20 - Typical Stress -Strain Curve of Compression 

 Specimen Taken fronn Nascent Titanium Alloy 

 Bar Used in Models OV-3 and OV-4 



has been partially answered by the tests of the four -diameter -long 

 machined Models OV-4 and OV-5. 



GENERAL-INSTABILITY MODE OF COLLAPSE 



The tests of Model OV-4, which was four diameters long, were in- 

 tended to provide an insight into the possible reduction in collapse strength 

 and change in mode of failure which might be expected in the case of a 

 long compartment. The tests of Model OV-5 were intended to determine 

 whether a redesign, slanted toward increasing the general-instability 



28 



