Need a book? Engineering books recommendations...

Return to index: [Subject] [Thread] [Date] [Author]

# Column with unknown axial load

[Subject Prev][Subject Next][Thread Prev][Thread Next]
• To: "Sseaint Org" <seaint(--nospam--at)seaint.org>
• Subject: Column with unknown axial load
• From: "gregory szuladzinski" <ggg(--nospam--at)bigpond.net.au>
• Date: Fri, 4 Mar 2011 20:40:50 +1100

 Reply:   One of the ways to test is to measure frequency of lateral vibrations. Tension will increase, compression decrease. (One of the ways to determine elastic buckling is to say that zero frequency is achieved at that state.) The formula is quite simple and can be found in many sources.   An easy task would be if no other column was directly above this one. You could then place two different weights above and measure two different frequencies. This would define the whole range including no-load point.   Sincerely Gregory from Oz       Question:   From: "Jorge Jimenez" To: Subject: Zero stress columnI have a column resisting heavy loads in an industrial warehouse. The =lowerpart of the column should be removed to allow a projected circulating =space.I am designing a reaction frame to carry out the load from the upper =part ofthe column, with an special movable connection intended to reduce thevertical movement above the column cutting point in the moment of thecut-off of the lower part of the column. The perfect moment for the =cuttingof the columns is when compression stresses become near to zero. It is =noteasy to estimate closely the existing load on the column. I am wondering =ifit's possible to detect the change from compression to tension in the =columnwith not invasive tests. Something able to detect any special =characteristicof the steel internal structure being different in compression and intension. Any help?