Evaluation of uncertainty in experimental active buckling control of a slender beam-column with disturbance forces using Weibull analysis

• It is found that the load capacity of the beam-column could be increased by 40% and scatter of buckling occurrences for increasing axial loads is reduced in the experimental test setup.
• Axial load and lateral deflection of the beam-column with and without active buckling control are measured for a number of sample trials to, eventually, evaluate uncertainty.
• Weibull analysis is used to evaluate the increase of the load capacity and its related uncertainty.
• As a result, uncertainty of the axial load capacity for both, the passive uncontrolled beam-column and for the beam-column with active buckling control and with defined disturbance forces is evaluated and compared to each other.

Buckling of slender load-bearing beam-columns is a crucial failure scenario in light-weight structures as it may result in the collapse of the entire structure. If axial load and load capacity are unknown, stability becomes uncertain. To compensate this uncertainty, the authors successfully developed and evaluated an approach for active buckling control for a slender beam-column, clamped at the base and pinned at the upper end. Active lateral forces are applied with two piezoelectric stack actuators in opposing directions near the beam-column' clamped base to prevent buckling. A Linear Quadratic Regulator is designed and implemented on the experimental demonstrator and statistical tests are conducted to prove effectivity of the active approach. The load capacity of the beam-column could be increased by 40% and scatter of buckling occurrences for increasing axial loads is reduced. Weibull analysis is used to evaluate the increase of the load capacity and its related uncertainty compensation.