Explain the follwing result, + 2 + -cos 20+xy sin 20 2 sin 20+xy cos 20...

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Explain the follwing result, + 2 + -cos 20+xy sin 20 2 sin 20+xy cos 20 2 a) What do the two equations tell us? Which area/cut do the two stress components in the left-hand sides exerted on? Sketch a 3D material element (triangular plate) to show all the stress components involved in the equations. Which angle does 0 stand for? b) What is principal plane, Principal direction, and principal stress? c) The following equations are usually used in calculating principal stresses, principal directions, and maximum shear stress, 01.2 = tan 20 = 2 y + + Tmax = R = = 720-02 2 2 2 tan 20 == 21. 25xy The equation about Op has multiple solutions, but your calculator can only give one. Another meaningful solution can be obtained by adding or subtracting /2. Now you have two principal stresses and two principal directions. If x is larger than Oy, which principal stress does Op from your calculator correspond to? Maximum shear stress occurs on the plane/cut that is 45 degrees away from the principal directions. On the cut that has maximum shear, which direction does the shear stress shearing toward, the maximum principal direction or the minimum principal stress direction? Explain the follwing result, + 2 + -cos 20+xy sin 20 2 sin 20+xy cos 20 2 a) What do the two equations tell us? Which area/cut do the two stress components in the left-hand sides exerted on? Sketch a 3D material element (triangular plate) to show all the stress components involved in the equations. Which angle does 0 stand for? b) What is principal plane, Principal direction, and principal stress? c) The following equations are usually used in calculating principal stresses, principal directions, and maximum shear stress, 01.2 = tan 20 = 2 y + + Tmax = R = = 720-02 2 2 2 tan 20 == 21. 25xy The equation about Op has multiple solutions, but your calculator can only give one. Another meaningful solution can be obtained by adding or subtracting /2. Now you have two principal stresses and two principal directions. If x is larger than Oy, which principal stress does Op from your calculator correspond to? Maximum shear stress occurs on the plane/cut that is 45 degrees away from the principal directions. On the cut that has maximum shear, which direction does the shear stress shearing toward, the maximum principal direction or the minimum principal stress direction?