Problem 552
A cantilever beam carries the force and couple shown in Fig. P-552. Determine the maximum tensile and compressive bending stresses developed in the beam.
 

Problem 551
Find the maximum tensile and compressive flexure stresses for the cantilever beam shown in Fig. P-551.
 

Problem 550
Resolve Prob. 549 if the maximum moments are +2.5P lb·ft and -5.0P lb·ft.
 

Problem 549
A beam with cross-section shown in Fig. P-549 is loaded in such a way that the maximum moments are +1.0P lb·ft and -1.5P lb·ft, where P is the applied load in pounds. Determine the maximum safe value of P if the working stresses are 4 ksi in tension and 10 ksi in compression.
 

Problem 548
The inverted T section of a 4-m simply supported beam has the properties shown in Fig. P-548. The beam carries a uniformly distributed load of intensity w_o over its entire length. Determine w_o if f_bt ≤ 40 MPa and f_bc ≤ 80 MPa.
 

Problem 543
A portion of the floor plan of a building is shown in Fig. P-543. The total loading (including live and dead loads) in each bay is as shown. Select the lightest suitable W-shape if the allowable flexural stress is 120 MPa.
 

Flexural Stress varies directly linearly with distance from the neutral axis. Thus for a symmetrical section such as wide flange, the compressive and tensile stresses will be the same. This will be desirable if the material is both equally strong in tension and compression. However, there are materials, such as cast iron, which are strong in compression than in tension. It is therefore desirable to use a beam with unsymmetrical cross section giving more area in the compression part making the stronger fiber located at a greater distance from the neutral axis than the weaker fiber. Some of these sections are shown below.
 

Problem 541
The 18-ft long floor beams in a building are simply supported at their ends and carry a floor load of 0.6 lb/in². If the beams have W10 × 30 sections, determine the center-line spacing using an allowable flexural stress of 18 ksi.
 

Problem 540
Timbers 8 inches wide by 12 inches deep and 15 feet long, supported at top and bottom, back up a dam restraining water 9 feet deep. Water weighs 62.5 lb/ft³. (a) Compute the center-line spacing of the timbers to cause f_b = 1000 psi. (b) Will this spacing be safe if the maximum f_b, (f_b)_max = 1600 psi, and the water reaches its maximum depth of 15 ft?