Dr Ranjan Vepa - Active Control of Fracture Toughness of Vibrating, Wind Turbine Rotor Blades
Date: Wed 16 May 2012, 15:00 - 16:00
After presenting a brief summary of his research activities, Dr. Ranjan Vepa will present a scheme for active control of fracture toughness of vibrating, wind turbine rotor blade structures based on nonlinear state estimation employing the unscented Kalman filters followed by the deployment of a structural controller to compensate for the damage. The measurements are obtained from accelerometers and strain gauges followed by estimation of the natural frequencies of the system. It is assumed that one can directly measure changes in the natural frequencies of the structure.
On detecting the damage in a region of maximum strain it is shown that it is possible to deploy a structural controller to compensate for the damage. The structural controller may be considered to be a compliance controller providing for the possibility of actively stiffening the damaged structure and also increasing the fracture toughness. However to be able implement such a controller it is required that a shape memory alloy (SMA) wires are embedded within the structure. The stiffening of the structure is facilitated by heating the wire so as to transform the wire from a martensite phase to an austenite phase. The results demonstrate the feasibility of the approach.