Design of a Morphing Wing-tip

An initial design of a morphing wing-tip for a Regional Jet aircraft is developed and evaluated. The adaptive wing-tip concept is based upon a chiral type internal structure, enabling controlled cant angle orientation, camber and twist throughout the flight envelope. A baseline Turbo-Fan Aircraft configuration model is used as the benchmark to assess the device. CFD based aerodynamics are used to evaluate the required design configurations for the device at different points across the flight envelope in terms of lift/drag and bending moment distribution along the span, complemented by panel method based gust load computations. Detailed studies are performed to show how the chiral structure can facilitate the required shape changes in twist, camber and cant. Actuator requirements and limitations are assessed, along with an evaluation of the aerodynamic gains from the inclusion of the device versus power and weight penalties. For a typical mission it was found that savings of around 2% in fuel weight are possible using the morphing wing-tip device. A similar reduction in weight due to passive gust loads alleviation is also possible with a slight change of configuration

Computational Homogenization of Architectured Materials

Architectured materials involve geometrically engineered distributions of microstructural phases at a scale comparable to the scale of the component, thus calling for new models in order to determine the effective properties of materials. The present chapter aims at providing such models, in the case of mechanical properties. As a matter of fact, one engineering challenge is to predict the effective properties of such materials; computational homogenization using finite element analysis is a powerful tool to do so. Homogenized behavior of architectured materials can thus be used in large structural computations, hence enabling the dissemination of architectured materials in the industry. Furthermore, computational homogenization is the basis for computational topology optimization which will give rise to the next generation of architectured materials. This chapter covers the computational homogenization of periodic architectured materials in elasticity and plasticity, as well as the homogenization and representativity of random architectured materials

Transformation spino-cellulaire de deux tumeurs de Buschke-Löwenstein

No Abstract. African Journal of Urology Vol. 11(3) 2005: 225-22