Aluminum rectangular bus deflection and fiber stress 1

[Yaling]

Hello, everyone,
I am looking at how aluminum bus bar behave during short circuit situation, there will be 40ksi tension stress on the bus at the point of support if supports spaced at 5ft. By checking the Aluminum hadbook, I got Aluminum 1350-Hiii minimum yield stress is only 3.5ksi, minimum ultimate stress is 8.5ksi and elongation percentage is 35%. my question is if the Aluminum bus bar is going to break or deflect as a spagatti. Btw, the short circuit normally force is one time thing and just last couple of seconds.

Simple Yes or No will help a lot, thanks indeed.

 

[rb1957]

i think you need to do a non-linear FEA 'cause 40ksi won't develop in 8.5ksi ftu Al. i suspect that this'll show the Al will deflect like hot spaghetti. this solution depends on whether there is a loadpath around the Al ... if there is it'll deflect, if there isn't it'll probably defelct and break.

 

[desertfox]

Hi Yalling

Yes your bar will fail.
Look at this site for stresses due to short circuit currents on copper busbars however the same formula apply for alumium.

http://www.copperinfo.co.uk/busbars/pub22-copper-for-busbars/sec6.htm#Electromagnetic

Stresses

desertfox