A survey on uncertainty in the control of an active column critical to buckling

Buckling of load-carrying column structures is an important design constraint in light-weight structures as it may result in the collapse of an entire structure. When a column is loaded by an axial compressive load equal to its individual critical buckling load, a critically stable equilibrium occurs. When loaded above its critical buckling load, the passive column may buckle. If the actual loading during usage is not fully known, stability becomes highly uncertain. This paper presents an approach to control uncertainty in a slender flat column structure critical to buckling by actively stabilising the structure. The active stabilisation is based on the excitation of the column in its second vibrating bending mode shape at its second eigenfrequency. This results in a bearable axial compressive load which can be theoretically three times higher than the actual critical buckling load of considered system. Finally, the sensitivity of the presented system will be discussed for the design of an appropriate controller for stabilising the active column.