41 0 Appendix A: Stress and strain analysis
- Calculate the rotation angle and direction from ox to q. Remember that
rotations on the circle are twice real life rotations (Q = positive rotation).
but be aware that 0" e @ e 180".correct orientation.- Finally, draw the element on which the principal stresses act, in the
Example10 1'"I .,. Cor110
- (2 x = 1 I.18Mpa centre = i(20 + 10) = =a
u, = 15 + 11.18 = 26.18MPa u2 = 15 - 11.18 = 3- T,,,~~ = 11 .I8MPa
0 =tan -' 20- ~ 10 = 63.43' :. 13 = 31.72'X \ u2 = 3.82MPa