Impact Loading
Impact Loading
(OP)
I have a problem. I have an overhead crane that carries 25 tons and moves at 0.5mph. I am incharge of designing the protection so it won't accidently hit something really important. It is designed as basically a jail cell around the important item, what loads should I use when I am designing the the jail cell bars. I think it is a basic impact question. Does i use the full capcaity? 25 tons? more? Less?
Thanks for any opinions or help.
Thanks for any opinions or help.






RE: Impact Loading
RE: Impact Loading
Or you can dig out your college books to find solution using energy method.
RE: Impact Loading
Either make it showck absrobing or build it like a tank...
RE: Impact Loading
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Don Phillips
http://worthingtonengineering.com
RE: Impact Loading
Trolley wheel stops however should be designed to resist momentum forces.
RE: Impact Loading
E = 1/2 m v^2
This must be absorbed by the impact protection structure as internal work. If repeated impacts are likely, you might want the protection structure to be able to absorb this much kinetic energy as fully recoverable elastic strain energy with no permanent deformation. For a linearly elastic system, the elastic strain energy is given by:
W = 1/2 F U
where F is the maximum reaction force and U is the corresponding displacement. Equate E with W, and you are well on the way to working out whether your protection structure can absorb the kinetic energy of the lifted mass.
If impacts are rare "worst-case" scenarios, you might allow the impact strcuture to undergo some permanent deformation for a full impact. (I.e. design a sacrificial protection strcuture, which may need to be repaired or replaced after a major impact.) In this case, you will find the energy absorption of a well-designed ductile frame can be MUCH higher than its elastic capacity, as large amounts of work are required to permanently deform plastic hinges etc.
Hope this helps!