
#1
Nov1513, 01:15 PM

P: 9

Hi
So I'm trying to find out how much force a tin can, can support before failing. The can will be stood up as it should be with a force applied over the top across the area of the can. I've tried the process of short column buckling to no avail. I've also tried axial and hoop stress for thin walled pressurized vessels. I keep getting silly numbers and am now completely lost. Also, would you assume that pressure inside the can is the same as atmospheric? So here are the numbers: Length = 109mm Diameter = 74mm Assumed yield stress of 590n/mm^2 Atmospheric pressure = 0.101325n/mm^2 Any direction or help would put my mind at ease, thanks I've found http://ntrs.nasa.gov/archive/nasa/ca...1969013955.pdf Is page 14 the part im look for? Thanks again. 



#2
Nov1513, 02:12 PM

HW Helper
Thanks
P: 5,578

Without knowing the thickness of metal in the can, you won't be able to even hazard a guess. It is also important to know if the sides of the can are rolled straight or if they might have any corrugations.




#3
Nov1513, 02:27 PM

P: 9

Yea, sorry forgot to include that...
Thickness = 0.4mm The sides are corrugated, but im just after the basic theory of the crushing force needed. I've got 53683.1N using Axial stress for thin walled cylinders Also tried a basic calculation of Stress = F/A + Pressure*pi*r^2 and rearrange for F I've also found that the internal pressure of a can of beans is 30psi or 206842.72 N/m^2 Thanks alot 



#4
Nov1713, 02:08 PM

P: 9

Forces on a pressurized tin can of beans
No ideas? :<




#5
Nov1713, 03:29 PM

HW Helper
Thanks
P: 5,578

If your can of beans has an internal pressure of 30 psi, I suspect that the beans have spoiled. Usually, canned food is vacuum packed to eliminate any air inside the can which might promote spoilage of the contents. Carbonated beverages obviously are an exception, as the internal pressure inside the can provides resistance to collapse of the can.




#6
Nov1713, 03:43 PM

P: 9

If the can is vacuum packed, wouldn't that mean the tin has negative internal pressure and would deform laterally?




#7
Nov1713, 06:03 PM

HW Helper
Thanks
P: 5,578

Not necessarily. Although cans are not infinitely strong, they do have some strength. That's why the thickness of the metal and what kind of corrugations are important in trying to determine the strength of the can. After all, even if a perfect vacuum forms inside the can, the maximum atmospheric pressure is still only about 15 psi.




#8
Nov1713, 08:35 PM

Engineering
Sci Advisor
HW Helper
Thanks
P: 6,379

With the OP's can dimensions, 15 psi is about 100 pounds force on each end of the can. Somebody weighing 200 pounds might be able to stand on two bean cans without crushing them, but if the experiment failed it would make quite a mess. 


Register to reply 
Related Discussions  
Magic beans problem  Set Theory, Logic, Probability, Statistics  25  
Baked beans  General Discussion  14  
Fluid mechanics question on forces on a cone in a pressurized tank  Engineering, Comp Sci, & Technology Homework  0  
bean weight brain teaser  Brain Teasers  6  
A horror of birds and beans  General Discussion  0 