FIGURE P$1-40$

Frame for Problem $1-40$

$1-41.$ Use Figure P$1-41.$

$($b$)$

$($c$)$

$($d$)$

FIGURE P$1-41$

Truss for Problem $1-41$: $($a$)$ Layout of the truss, its supports, and the applied load; $($b$)$ cross section of members $AB,BC$; $($c$)$ cross section of member $BD$; and $($d$)$ cross section of members $AD,CD.$

$1-31.$ A shelf is being designed to hold crates having a total mass of $1650$ kg $.$ Two support rods like those shown in Figure P$1-31$ hold the shelf. Each rod has a diameter of $12\mathrm{.}0$ mm $.$ Assume that the center of gravity of the crates is at the middle of the shelf. Compute the stress in the middle portion of the rods.