Active Repair and Control of Imperfect Slender Structures Under Compression

Slender beams and plates are the most commonly used structural components in civil engineering. Initial cracks and geometric imperfections in the existing structures make them vulnerable to buckling instability or failure due to excessive post-buckling deflections when subjected to compressive loads. Active repair and control of these imperfect structures have great potential in regaining and enhancing their loadcarrying capacity.This project will investigate numerically and experimentally the active control of the post-buckling behavior of imperfect slender beams and plates through the use of repair patches and surface bonded piezoelectric sensors and electroactive polymer actuators. The theoretical formulation will be based on von Karman nonlinear kinematics and takes into account the effects of various imperfection modes and material nonlinearity in the adhesive layer. An optimization algorithm will be used for the design of repair patch and sensor/actuator array rendering maximized critical buckling load and minimized post-buckling deflections. The research outcome will lead to not only an in-depth understanding of the nonlinear electro- mechanical characteristics but also an effective and economical control technique of structures with initial cracks and imperfections, thus improving the performance reliability and extending the service life of existing structures.