Gust alleviation of a large aircraft with a passive Twist Wingtip

This paper presents an investigation into the gust response and wing structure load alleviation of a 200-seater aircraft by employing a passive twist wingtip (PTWT). The research was divided into three stages. The first stage was the design and analysis of the baseline aircraft, including aerodynamic analysis, structural design using the finite element (FE) method and flutter analysis to meet the design requirements. Dynamic response analysis of the aircraft to discrete (one-cosin) gust was also performed in a range of gust radiances specified in the airworthiness standards. In the second stage, a PTWT of a length of 1.13 m was designed with the key parameters determined based on design constraints and, in particular, the aeroelastic stability and gust response. Subsequent gust response analysis was performed to evaluate the effectiveness of the PTWT for gust alleviation. The results show that the PTWT produced a significant reduction of gust-induced wingtip deflection by 21% and the bending moment at the wing root by 14% in the most critical flight case. In the third stage, effort was made to study the interaction and influence of the PTWT on the symmetric and unsymmetrical manoeuvring of the aircraft when ailerons were in operation. The results show the that PTWT influence with a reduction of the aircraft normal velocity and heave motion by 1.7% and 3%, respectively, is negligible. However, the PTWT influence on the aircraft roll moment with a 20.5% reduction is significant. A locking system is therefore required in such a manoeuvring condition. The investigation has shown that the PTWT is an effective means for gust alleviation and, therefore, has potential for large aircraft application

DEVASPIM: desarrollo de una herramienta para el diseño y evaluación de implantes de raquis

The IBV participates in the European project DEVASPIM (www.devaspim.com) to develop a tool for the design and evaluation of lumbar spine implants by an analytic calculation. The tool will help the surgeons to plan the intervention by contributing with the information about the biomechanical behaviour of the assembling spine-implant and the implant manufacturers by improving the design, reducing in both cases the probability of failure of the implant. The biomechanical behaviour calculated by the tool will be obtained with a FEM model adapted to the specific case. The technical specifications defining the tool are described in this article.CON EL OBJETIVO DE DESARROLLAR UNA HERRAMIENTA DE DISEÑO Y EVALUACIÓN DE implantes de raquis lumbar mediante el cálculo analítico, el IBV está desarrollando el proyecto europeo DEVASPIM (www.devaspim.com). La herramienta ayudará a los cirujanos a realizar una planificación preoperatoria aportándoles la información sobre el comportamiento biomecánico del conjunto raquis-implante y a los fabricantes de implantes a mejorar el diseño, reduciendo en ambos casos la posibilidad de fallo del implante. Este comportamiento biomecánico calculado por la herramienta se obtendrá mediante la simulación numérica con un modelo de elementos finitos adaptado al caso propuesto por el usuario. Las especificaciones técnicas que definen la herramienta son expuestas en el artículo