2. Maximum principal stress theory

Try these first

1. 1.

   What is the definition of principal stress?

   Hint

   Think about how stress varies within a material.

2. 2.

   What test is commonly used to find the critical value of stress?

   Hint

   Consider what happens when we pull a material.

3. 3.

   What test is used to determine critical stress values?

   • Impact Test
   • Tensile Test
   • Bending Test

   Hint

   Think about what happens when we stretch a material.

4. 4.

   True or False: Principal stress refers to both maximum and minimum normal stresses.

   • True
   • False

   Hint

   Reflect on the definition of principal stress.

5. 5.

   Calculate the yield strength of a copper wire that fails under a tensile load of 2500N applied to 1.5mm in diameter.

   Hint

   Convert diameter to radius and remember to calculate area correctly.

6. 6.

   A solid cylindrical shaft with a diameter of 50mm transmits a torque of 500Nm. Calculate the maximum shear stress experienced by the shaft.

   Hint

   Use the polar moment of inertia for a solid circular shaft in your calculations.