· If the strut is to be used in compression the question of stability must be considered: Will the strut buckle before it plastically deforms?
· The diagram shows a rod loaded longitudinally in compression and tested for stability against small transverse displacements.
· For the compressive force, F, less than some critical value, F_C , the rod will become straight when the transverse force, F_h , is removed.
· For F < F_C the rod is stable , and for F > F_C the rod buckles and fails.