# Mohr's Circle

by fugg
Tags: circle, mohr
 P: 34 Since you can find $$2\varphi$$, the angle between principle stress and normal stress is $$\varphi$$. If you draw your mohr's cicle, the rest will be only a metter of rotating $$\varphi$$ degress from horizontal axis to find principle stress direction. In geometry, round angle is half of centre angle; that's where pole comes from. From above picture, you can see the angle between blue line and horizontal axis is $$\varphi$$ (Orange line is parallel to horizontal axis). For stresses on any other planes, no matter pole or whatever, just use your geometry skills. It won't be more difficult than your middle school geometry class. Good Luck.