PSG College of Technology, Coimbatore 641 004Department of Production Engineering08P601 Design of Machine Elements

Tutorial – III, Curved Beams

1. A utility hook was formed from a round rod of diameter d = 20 mm into the geometry shown in the figure 1. What are the stresses at the inner and outer surfaces at section A–A if F = 4 kN,

2. The steel eyebolt shown in the figure 2 is loaded with a force F = 300 N. The bolt is formed from wire of diameter d = 6 mm to a radius R = 10 mm in the eye and at the shank. Estimate the stresses at the inner and outer surfaces at section A–A. Also estimate the stresses at the inner and outer surfaces at section B–B.

3. Shown in the figure 3 is a 12-gauge (2.7787 mm) by 19.25 mm latching spring that supports a load of F = 13.35 N. The inside radius of the bend is 3.175 mm. Using straight-beam theory, determine the stresses at the top and bottom surfaces immediately to the right of the bend. Using curved-beam theory, determine the stresses at the inner and outer surfaces at the bend. By comparing the stresses at the bend with the nominal stresses before the bend, estimate effective stress concentration factors for the inner and outer surfaces.

4. The crane hook carries a load of 20 kN as shown in figure 4. The section at X-X is rectangular whose horizontal side is 100 mm. Find the stresses in the inner and outer fibers at the given section.