A horizontal shelf AD of length L = 915 mm, width b 305 mm, and thickness t = 22 mm is supported by brackets at B and C [see part (a) of the figure]. The brackets are adjustable and may be placed in any desired positions between the ends of the shelf. A uniform load of intensity q, which includes the weight of the shelf itself, acts on the shelf [see part (b) of the figure].
Determine the maximum permissible value of the load q if the allowable bending stress in the shelf is σallow= 7.5 MPa and the position of the supports is adjusted for maximum load carrying capacity.
