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A morphing leading edge produces a continuous aerodynamic surface that has no gaps between the moving and fixed parts. The continuous seamless shape has the potential to reduce drag, compared to conventional devices, such as slats that produce a discrete aerofoil shape change. However, the morphing leading edge has to achieve the required target shape by deforming from the baseline shape under the aerodynamic loads. In this paper, a conceptual-level method is proposed to evaluate the morphing leading edge structure. The feasibility of the skin design is validated by checking the failure index of the composite when the morphing leading edge undergoes the shape change. The stiffness of the morphing leading edge skin is spatially varied using variable lamina angles, and comparisons to the skin with constant stiffness are made to highlight its potential to reduce the actuation forces. The structural analysis is performed using a two-level structural optimisation scheme. The first level optimisation is applied to find the optimised structural properties of the leading edge skin and the associated actuation forces. The structural properties of the skin are given as a stiffness distribution, which is controlled by a B spline interpolation function. In the second level, the design solution of the skin is investigated. The skin is assumed to be made of variable stiffness composite. The stack sequence of the composite is optimised element-by-element to match the target stiffness. A failure criterion is employed to obtain the failure index when the leading edge is actuated from the baseline shape to the target shape. Test cases are given to demonstrate that the optimisation scheme is able to provide the stiffness distribution of the leading edge skin and the actuation forces can be reduced by using a spatially variable stiffness skin. [ABSTRACT FROM AUTHOR]

Unwanted vibrations are a common occurrence within structures and systems, and often pose a threat to their integrity or functionality. This research aims to seek a solution to attenuate the vibrations experienced within a link of a system using active vibration control with piezoelectric patches as actuators, whilst avoiding the use of large and expensive equipment which would contravene with the common objective of maintaining the smallest mass possible of the system. Previous research has employed large and expensive equipment as the controller, with sensors often only being able to measure the vibrations of the structure along one axis; this research aims to address these issues. The choice of utilizing the small, lightweight, and low-cost Raspberry Pi 3 combined with petite, mountable sensors and actuators was made based upon the greater practicality that the controller, sensors, and actuators exhibit, allowing for their use in a wide variety of applications. An analytical model of the structure was created based on Euler–Bernoulli beam theory and validated through the modal parameters and the frequency response obtained from a finite element model and experimental data. A controller was then designed and applied to the analytical model to attenuate the vibrations along the link, and then the same design was implemented within the Raspberry Pi 3, and experimental studies were carried out. The introduction and effectiveness of a purposeful time delay within the controller was explored within the experimental and analytical studies, with the intention of counteracting unfavorable results produced by the control system. The results of the experiment proved the control design to be effective for a range of frequencies that included the first natural frequency of the link, and validated the analytical model including the control design. [ABSTRACT FROM AUTHOR]