x-axis
y-axis
80 mm
170 mm
0
Question 4 (75 marks):

The section is formed from a semicircle (radius = 80 mm) and a triangle (base = 160 mm, height = 170 mm), with a circular hole (radius = 40 mm) removed.

Calculate Ix, the moment of inertia about the x-axis.

Calculate ICy, the moment of inertia about the centroidal y-axis.

Find the y coordinate, ybar , of the centroidal x-axis.

Find the x and y radii of gyration about the x- and y- axes

Solution:
 
Ix =
x 106 mm6
 
ICy =
X 106 mm6
 
ybar =
mm
 
rx =
mm
 
ry =
mm