Three identical, solid circular rods, each of radius r and length L, are placed together to form a compression member (see the cross section shown in the figure).
Assuming pinned-end conditions, determine the critical load Pcr as follows:
(a) The rods act independently as individual columns, and
(b) the rods are bonded by epoxy throughout their lengths so that they function as a single member.
What is the effect on the critical load when the rods act as a single member?