Shear force and bending moments
1. Draw the free-body diagram (FBD).
2. Determine the reaction of supports at points A and D.
3. Draw the shear diagram.
4. Draw the bending moment diagram under and vertically aligned with the shear diagram.
5. Locate the section where the bending moment is maximum. This is the critical section that will govern the design.
6. Calculate the nominal bending stress σbnom at the outer surface of the critical section.
7. What is the shear stress due to shear force at the center of the critical section?
8. Determine the stress concentration Kt, in bending, for a sled-runner keyseat.
9. Using the stress concentration factor Kt just determined, calculate the bending stress σb.
10. Determine the magnitude and the location of the maximum deflection ymax of the beam.
11. Based on your calculations of bending stress alone, does the shaft meet your design criteria determined in the first part of the project? If not, suggest a new shaft diameter that will satisfy your criteria.
a. Are the value of the maximum deflection ymax due to transversal load acceptable for a power transmission shaft such as the one under consideration? Why?
b. Give two reasons why the shear stress due to shear force are not relevant for this section?