Problem 515
Repeat Prob. 524 to find the maximum flexural stress at section b-b.
 

Problem 514
The right-angled frame shown in Fig. P-514 carries a uniformly distributed loading equivalent to 200 N for each horizontal projected meter of the frame; that is, the total load is 1000 N. Compute the maximum flexural stress at section a-a if the cross-section is 50 mm square.
 

Problem 511
A simply supported rectangular beam, 2 in wide by 4 in deep, carries a uniformly distributed load of 80 lb/ft over its entire length. What is the maximum length of the beam if the flexural stress is limited to 3000 psi?
 

Problem 510
A 50-mm diameter bar is used as a simply supported beam 3 m long. Determine the largest uniformly distributed load that can be applied over the right two-thirds of the beam if the flexural stress is limited to 50 MPa.
 

Problem 509
A section used in aircraft is constructed of tubes connected by thin webs as shown in Fig. P-509. Each tube has a cross-sectional area of 0.20 in². If the average stress in the tubes is no to exceed 10 ksi, determine the total uniformly distributed load that can be supported in a simple span 12 ft long. Neglect the effect of the webs.
 

Problem 508
Determine the minimum height h of the beam shown in Fig. P-508 if the flexural stress is not to exceed 20 MPa.
 

Problem 507
In a laboratory test of a beam loaded by end couples, the fibers at layer AB in Fig. P-507 are found to increase 60 × 10^-3 mm whereas those at CD decrease 100 × 10^-3 mm in the 200-mm-gage length. Using E = 70 GPa, determine the flexural stress in the top and bottom fibers.
 

Problem 506
A flat steel bar, 1 inch wide by ¼ inch thick and 40 inches long, is bent by couples applied at the ends so that the midpoint deflection is 1.0 inch. Compute the stress in the bar and the magnitude of the couples. Use E = 29 × 10⁶ psi.