Mechanics of Materials: Lesson 49 - Max Shear and Principal Stress with Equation Method

I'm back we're talking about stress transformation and this really is a continuation from the last video in the last video we talked about distress transform equations these top three equations here okay now we talked about stress we said stress is directional so if I have a stress element as I start to rotate it then that's wrong Stripes is stressed out he needs some help with stress equations too do you need stress equation help okay let's go okay you gotta go back come on you gotta go out come on you gotta go out okay come on okay go all right all right we said stress is directional so as I start to rotate a stress element right these numbers the normal stresses and these numbers the shear stresses start to change they'll go up they'll go down but what they'll eventually do is they'll go to a maximum place and th and then once they get to a maximum just think about like if I'm going to throw a ball if I throw it at 45 degrees I'm going to get maximum if I throw it any higher than that I'm going to get less if I throw it any lower than that I'm going to get less distance right same thing for stress stress is maximum at 45 degrees so as I go to 45 degrees well that's not true so same thing for stress stress there is a direction where this the normal stress is going to be maximum and there is another Direction Where shear stress is going to be maximum okay so last time we just found out let's just transform this to some random angle right and we could use these equations to transform it to any angle in the world we want and I'll tell you what the new Sigma X is