Part2A, 2B, and Discussion

 

I'll need answers, formulas, and work shown please. 

 

Part 2A  Torsional Key Design 

1. Choose a key material from Table 02 above and document your choice of material and temper in your work.
2. Using your Part 1 torque values (problem 15) T_B and T_C determine force F that the shaft exerts on the keys.
3. Based on the given shaft diameter, use Diagram 2 to find the b and h values for your key.  NOTE: t = h/2 or t =d/8 are only for really small shaft diameters.
4. Using the shear force F from #2 above and shear stresses ?_B and ?_C (from Part 1C #20) find area A_s required (see Diagram 1) to support the shear load. (Hint see EQN 1-5)
5. Determine your key length L, good design practice requires length L = 2b minimum. Determine both values and compare.
6. What is your chosen key materials Factor of Safety (FOS)?  (Key requirement, ?_d > ?)

Part 2B  Combined Stresses and Buckling

1. Combine the stresses due to normal bending (Part 1A) and column type compression (Part 1B) using superposition. Refer to Diagram 3 (textbook Figure 10-21 modified) and textbook Figure 8-18 for visualizing the combination.
2. In #7 above you found the combined stresses for the shaft top and bottom. State which is maximum?
3. Calculate the maximum shear stress using the equation developed in our textbook page 571 (shown here).

   Image transcription text

   T max V(ox/2) + T

4. What is your chosen shaft materials yielding Factor of Safety (FOS) relative to ?_max?

Part 2C  Considering Buckling

1. First determine the end fixity values for the two bearing types supporting the shaft.  From textbook Figure 11-3. 
2. Second find the radius of gyration, r, for our shaft using textbook Appendix A-1.
3. Compute the slenderness ratio SR of the shaft. (Hint see EQN 11-1)
4. Determine the transition slenderness ratio C_C of the shaft. (Hint see EQN 11-3)
5. Would this shaft be considered a long or short column? Substantiate your reasons why.
6. Determine the critical load P_cr of the shaft using the appropriate formula.

Discussion (compute the values requested before writing an answer)

1. According to the maximum shear stress theory of failure, will this shaft safely transmit the load?  Substantiate your reasons why.
2. Would this shaft safely resist the compressive buckling load?  Substantiate your reasons why.
3. Is it reasonable to consider buckling in the design of this shaft? Substantiate your reasons why.

 

Below are images to help with the assignment. 

 

 

Image transcription text

Diagram 1 Hub Shear plane F2 T = Torque T = F(D/2) F1 = Force of shaft on key Fa = Force of hub on
key --D = Shaft diameter Side view End view Metric Standard Parallel Keyway and Key Sizes Shaft
Diameter Keyway Key Diagram 2 mm (mm) (mm)* From To Width Depth Width Depth (W) (... 

Image transcription text

Example of Bending Stress in Shaft (Figure 10-21) - Modified Diagram 3 Maximum Compressive Stress
Total Shaft Compression Neutral mis Maximum Tensive Stress PO Load Thrust Bearing

Image transcription text

Bending Stress Concentration Factor Diagram 4 Semi-circular end keyseat 4.0 3.8 3.6 3.4 Enlarged
view 3.2 of fillet 3.0 B 1 = d/8 2.8 M 15 2.6 Kt 2.4 2.2 2.0 KLA 1.8 1.6 1.4 1.2 1.0 0.000 0.005 0.010 0.015
0.020 0.025 0.030 0.035 0.040 r/d

Image transcription text

Problem Statement The horizontal shaft carries two 1|nil-belt pulleys, locations B and C, and rides on
two bearings at A and D. The tensile forces in the belts under operating conditions are shown as F31,
F52, FB1 and F62. Also. the shaft carries an axial compressive load of Pt]. You may disrega... 

Image transcription text

AB BC CD DS FC1 FC2 DPB pulley A B C D Po Bearing Thrust Bearing FB1 FB2 DPC pulley DRAWING
NOT TO SCALE Course Project - KEY Material Table CAL OF Part 1 Direct Compression stress and
deformation For step 13 make of choice for key material from this selection Material Elong... 

Image transcription text

Where Imay= maximum shear stress at the same point where o and @ occur o= tensile or compressive
stress creates by various loads T= shear stress creates by various loads