A bear managed to bend a steel door to a food locker in Yosemite. The
door is hinged on one side and pinned on one corner ( the camper forgot
to close it properly!!) , so the bend is across the diagonal. I
wondered how much force the bear had to use to bend it. The doors are
about 24" square and about .1" thick.
Anyone have any ideas? My calculations based on sheet metal bending
formula come out to nearly 7000 pounds., and I do not think a bear can
have that much strength. I have a jpg of the
bent door if anyone would like to see.

motor man wrote:
A bear managed to bend a steel door to a food locker in Yosemite. The
door is hinged on one side and pinned on one corner ( the camper forgot
to close it properly!!) , so the bend is across the diagonal. I
wondered how much force the bear had to use to bend it. The doors are
about 24" square and about .1" thick.
Anyone have any ideas? My calculations based on sheet metal bending
formula come out to nearly 7000 pounds., and I do not think a bear can
have that much strength. I have a jpg of the
bent door if anyone would like to see.


I think the force number is for a small radius bend, while the bear was
not concerned with bend radius. Also if two guys could grip a door and
pull on it without cutting themselves[like if they had claws] I think
they could do a similar job

On 13 Feb 2006 08:06:03 -0800, "motor man" wrote:

A bear managed to bend a steel door to a food locker in Yosemite. The
door is hinged on one side and pinned on one corner ( the camper forgot
to close it properly!!) , so the bend is across the diagonal. I
wondered how much force the bear had to use to bend it. The doors are
about 24" square and about .1" thick.
Anyone have any ideas? My calculations based on sheet metal bending
formula come out to nearly 7000 pounds., and I do not think a bear can
have that much strength. I have a jpg of the
bent door if anyone would like to see.

Using yield strength of 50 KSI, I figure about 120 lb of force would
do the job.

On 13 Feb 2006 10:05:45 -0800, with neither quill nor qualm, "motor
man" quickly quoth:

120 pounds sounds about right to me. The bear only weighed about that!

120 lbs of bear might easily have 300 lbs of pull, though, and if
jumping up and down while hanging on it, maybe 700-800 lbs.

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