Christopher J. Brampton

Level Set Topology Optimisation of Aircraft Wing Considering Aerostructural Interaction

Topology optimisation is the most general form of structural optimisation, capable of calculating the optimal arrangement of material in a loaded structure. Low weight efficient structures are vital to aircraft performance making aerospace structures an ideal field for the application of topology optimisation. In this investigation 3D level set topology optimisation is developed to optimise the internal structure of an aircraft wing with coupled aerostructural interaction. The results suggest that an alternative configuration of I-beam like wing with columns may be an optimal solution for wing structures. They also show the importance of considering the relationship between the internal wing structure and its aerodynamic performance. The paper thus, demonstrates potential benefits of Aerostructural 3D level set topology optimisation for a design of aircraft wing.

Actuation of Bistable Laminates by Conductive Polymer Nanocomposites for use in Thermal-Mechanical Aerosurface De-icing Systems

This paper considers a novel electro-thermal system combining aligned carbon nanotubes (A-CNT) as a resistive heater and bistable laminates. The use of A-CNT heaters to actuate bistable laminates is characterized in terms of steady-state shape as a function of applied voltage to the heating element and the transient response of the laminate to heating. Snap-through from one stable state to another was successfully achieved with a linear relationshiop between laminate curvature and applied voltage up to the snap-through event. Thermal actuation of a bistable wing skin has the potential for an efficient multifunctional thermo-mechanical ice protection system (IPS); using heat to address antiand de-icing, and secondly using thermal actuation of the bistable laminate to deform or mechanically disturb the skin to initiate debond of the ice-skin interface.

Simultaneous optimisation of structural topology and material grading using level set method

Abstract The present paper introduces a new technique for simultaneously optimising the topology and continuous material distribution of a structure. Topology optimisation offers great potential for novel, improved structural designs and is an ideal design tool for additive manufacturing (AM) techniques. Level set based topology optimisation produces solutions with clear, smooth boundaries that can be directly fabricated using AM. Further benefits of AM may be realised by also optimising the material distribution within the structure. The sequential linear programming level set method is used to include material distribution design variables in the topology optimisation problem. This allows the topology and continuous material distribution to be optimised simultaneously. Several compliance minimisation problems are used to demonstrate the proposed approach.

Investigation of aligned conductive polymer nanocomposites for actuation of bistable laminates

In this paper the coupled electro-thermo-mechanical actuation of bistable laminates using aligned carbon nanotubes is investigated. Applications for such actuators include ice protection systems (IPS) for aerosurfaces that can dislodge ice accretion via a combination of thermal and mechanical mechanisms. This study presents both new experimental results and multi-physics finite element modelling of the actuation and the resulting large deformation, focusing on both static and transient performance characterization.

Applications of 3D Level Set Topology Optimization

Level set topology optimization defines the solution using the level set function values stored at the nodes of a regular finite element grid. These values represent a signed distance function which indicates the distance from each node to the structural boundaries. During optimization, nodal sensitivities are used to update the level set function values, moving the boundaries to create a more optimal structure. This paper presents two applications of the 3D level set topology optimization procedure aiming to minimize structural compliance subject to a volume constraint. The first application is the internal structure of a light subsonic aircraft wing. The results suggest that an alternative arrangement of ribs and sparse may be a more optimal solution for wing structures. The second application is the internal trabecular bone structure of an os-calcis. Comparison of the modeled optimal structure and the real internal structure suggest the internal bone structure is mechanically optimal.Copyright