The element is subjected to plane stress. To determine the normal stress over section AB the transformation equation shown is used. Which of the following is the correct angle to be used?
σy
BTxy
20°
σχ
A
σχ
σχ
σχεση
x
2
y
0-40
0-70
20
40
-20
70
σχισ
y
+
cos 20 + 1x sin 20
xy
2