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3. The attempt at a solution

hi im having trouble with findin second moment of a T-beam.

here are the measurements of the beam:

http://img354.imageshack.us/img354/8648/beam6xl.jpg [Broken]

I have found the neutral axic fro the beam

and tht is 11.943 mm from the bottom rectangle

for 3nd moment of area

i have separated the two rectangles and calculated for each

Ixx= (6.4*(31.7)^3)/12+6.4*31.7*(10.4)^2 for the upper rectablge

Ixx= (38.1*(6.4)^3)/12+6.4*38.1*(8.65)^2 for the bottom rectangle

Then i added both and i got 5.8*10^-8 m^4

Then i had to find out the maximum stress for maxmimum load i.e for 84 Nm

i used the formula Stree= bending moment * neutral axis maximum/ 2nd moment of area

when i calculate it i dont get the same value as done in the practical i gues there is something wrong with my calculation in Ixx so plz can you tell me wht am i doing wron here

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# Homework Help: Need some help with finding the 2nd moment of area

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