Problem 569
Show that the maximum shearing stress in a beam having a thin-walled tubular section of net area A is τ = 2V / A.
Problem 568
Show that the shearing stress developed at the neutral axis of a beam with circular cross section is τ = (4/3)(V / π r2). Assume that the shearing stress is uniformly distributed across the neutral axis.
Problem 567
A timber beam 80 mm wide by 160 mm high is subjected to a vertical shear V = 40 kN. Determine the shearing stress developed at layers 20 mm apart from the top to bottom of the section.
Problem 564
Repeat Prob. 563 using 2-in. by 10-in. pieces.
Problem 563
A box beam is made from 2-in. by 6-in. pieces screwed together as shown in Fig. P-563. If the maximum flexure stress is 1200 psi, compute the force acting on the shaded portion and the moment of this force about the NA. Hint: Use the results of Prob. 562.
Problem 562
In any beam section having a maximum stress fb, show that the force on any partial area A' in Fig. P-562 is given by F = (fb/c)A'(barred y') , where (barred y') is the centroidal coordinate of A'. Also show that the moment of this force about the NA is M' = fb I'/c, where I' is the moment of inertia of the shaded area about the NA.
