Hints and Discussion Thread
- Recall that for any ideal pulley, the cable tensions on each side of the pulley are the same. In this case, the tensions in sections BC, CD and DH of the pulleys are all the same.
- Draw an FBD of the pulley centered at C. Solve for the x- and y-components of the reactions at C using the equilibrium equations for the pulley. From this, you can determine the shear force acting on each of the cross-sections of the double-sided pulley pin at C, and subsequently the shear stress in the pin at C.
- Repeat for pulley centered at D.
- Which of the pulley pins is critical in the design? Use the FS equation for the critical pulley pin.
Any questions? Ask (and answer) questions here.