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Discussion Starter #1
just wanted to make sure my battery racks will be strong enough:

if i'm using 1.25" x 1.25" .125" thick 6061 aluminum angle [tensile strength 45k psi, yield strength 40k psi]

can two bars support three T105 batteries [186 lbs total, 7" wide, 31" long] over a 32" span?

harry

Albuquerque, NM
current bike: http://www.austinev.org/evalbum/1179
current non-bike: http://evalbum.com/1000





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Discussion Starter #2
Hi Harry

Nope, that's probably not enough. It will hold, but with a very small factor of
safety (of about 1.3 ish, and giving a deflection of about 1.5mm in the middle),
so going over bumps etc will probably cause it to yield. For a road vehicle
designing for 5G acceleration is reasonable so you need 3 times what you suggest
- or 6 bars to your spec below to not yield under 5G loading. This is for simple
beam-like loading - if you constructed the rack as a box section rather than a
beam it would perform better and not need so much more material.

Hope that helps but this is only a rough calc...

Cheers
DaveW








----- Original Message ----
From: harry henderson <[email protected]>
To: Electric Vehicle Discussion List <[email protected]>
Sent: Sat, 27 November, 2010 4:49:58
Subject: [EVDL] aluminum battery rack strength check

just wanted to make sure my battery racks will be strong enough:

if i'm using 1.25" x 1.25" .125" thick 6061 aluminum angle [tensile strength 45k
psi, yield strength 40k psi]

can two bars support three T105 batteries [186 lbs total, 7" wide, 31" long]
over a 32" span?


harry

Albuquerque, NM
current bike: http://www.austinev.org/evalbum/1179
current non-bike: http://evalbum.com/1000





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| REPLYING: address your message to [email protected] only.
| Multiple-address or CCed messages may be rejected.
| UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
| OTHER HELP: http://evdl.org/help/
| OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev





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| Multiple-address or CCed messages may be rejected.
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