Analysis for Impact vs Constant Force?
Analysis for Impact vs Constant Force?
(OP)
I know how to analyze a structural system for a constant applied force, but what about impact forces? Are there some general tips or rules for what a structure might be able to handle in impact when it has been rated for a constant load? i.e. If a structure is rated to withstand a constant 5kN, can we estimate what sort of impact forces it would also withstand?
Thanks in advance!
Thanks in advance!





RE: Analysis for Impact vs Constant Force?
Check your mechanics of materials textbook under Strain Energy. This is where I was taught about impact loads.
Under impact, your structure must absorb the kinetic energy, somehow.
RE: Analysis for Impact vs Constant Force?
RE: Analysis for Impact vs Constant Force?
Regards,
Cockroach
RE: Analysis for Impact vs Constant Force?
Thus, you personally could survive a 200-g impact if it was sufficiently short, but a long duration impact would squash you flat. The difference is the time integral of the force, which is correlated with the total energy of the impact.
TTFN

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RE: Analysis for Impact vs Constant Force?
In the structure, TetWin11 would need to perform other basic calculations, of which we have no information. His general question got him a general answer. We have no idea of the collision, elastic or inelastic, material composition of bodies, deformation as a result thereof, impulse parameters, nothing. If the impact load was something on the order of 30 lbf in TetWin11 world, I would be considering his structure to statically withstand 90 lbf.
There would be other considerations of course. Just keeping it simple!
Regards,
Cockroach
RE: Analysis for Impact vs Constant Force?
It isn't actually a rule of thumb, it is a perfectly good piece of physics for a single degree of freedom system... that lazy engineers have misused.
Cheers
Greg Locock
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RE: Analysis for Impact vs Constant Force?
Tobalcane
"If you avoid failure, you also avoid success."
"Luck is where preparation meets opportunity"
RE: Analysis for Impact vs Constant Force?
Ted
RE: Analysis for Impact vs Constant Force?
Is that right?
Charlie
www.facsco.com
RE: Analysis for Impact vs Constant Force?
Now I need a new TV
Charlie
www.facsco.com
RE: Analysis for Impact vs Constant Force?
Ted
RE: Analysis for Impact vs Constant Force?
Cheers
Greg Locock
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RE: Analysis for Impact vs Constant Force?