## Second moments of area Izz and Ixx

1. The problem statement, all variables and given/known data

A vertical column has the horizontal cross sectional area shown in the attached image. The column carries a vertical compressive point load of 30kN applied at d. calculate the following:

a) The second central moments of area IZZ and Ixx
b) The maximum values of compressive and tensile stresses
c) The position on the cross section where the stress is zero

2. Relevant equations

3. The attempt at a solution

I have done part a and got:

Ixx = 5.48E+5
IZZ = 1.75E+5

for part b i know the formulas for compressive stress and tensile stress. However they require a bending moment number. How do i calculate this?

Tensile = Mzc/Ixx
Compressive M(zmax-Zc)Ixx

Compressive stress due to point load F/A

C) Im not sure how to complete this part

Any help would be much appreciated
Attached Thumbnails

 Recognitions: Homework Help Hint: Neutral Axis
 zc = 46.75mm and xc = 22.5mm. Is the bending moment calculated from these? I have been trying to work out the bending moment for a while now and cant seem to get the answer of 3.97E+5 Nmm

Recognitions:
Homework Help