Load Acting Eccentric to Both Axis:

If the axial load P is placed eccentric to both x-axis and y-axis as illustrated in Figure, after that the system might be assumed to consist of

1.  a direct compressive force P working at the centroid,

2.  a couple P × e_x around the x-axis, and

3.  a couple P × e_y around the y-axis.

As seen for the case of load working eccentric to one axis, the stress at any point might be written as

              f  =  f₀  + f_b1  ± f_{b 2}

                 = (P /A)± ( (P × ex ) /I _xx )× y ±( P × ey/I _xx)  × x

                   = (P/A) ± M _xx / Z _xx ± M _yy / Z yy

The maximum or minimum fibre stress shall occur at the corner point A, B, C or D in Figure for the symmetrical section.

Figure