E-TEST: a compact low-frequency isolator for a large cryogenic mirror

To achieve the expected level of sensitivity of third-generation gravitational-wave (GW) observatories, more accurate and sensitive instruments than those of the second generation must be used to reduce all sources of noises. Amongst them, one of the most relevant is seismic noise, which will require the development of a better isolation...

Seismic control performance of a three-story frame prototype equipped with semi-active variable stiffness and damping structural joints

This paper presents numerical and experimental studies on semi-active seismic response control of structures equipped with variable stiffness and damping structural joints. Such adaptive joints, which are comprised of a shape memory polymer (SMP) core reinforced by an SMP-aramid composite skin, function as load-transfer components as well as...

Controllability of solar-sail orbits in the Earth-Moon system

The propellantless nature of solar-sail propulsion allows researchers to design completely new sets of orbits unreachable or not-maintainable by means of conventional propulsion. The advantage of this somewhat new type of low-thrust propulsion system becomes more evident for long-duration missions where chemical or electrical rocket engines...

Application of Active Control System on the Seismic Response to Unreinforced Masonry Structure

The increase of the human-induced seismicity in the Groningen has increased the interest of all stakeholders to ensure the structural safety of all residents in the affected area. While there are already many conventional structural strengthening methods that are proposed and being implemented in the affected area, the study of a new innovative...

Active aeroelastic control aspects of an aircraft wing by using synthetic jet actuators: Modeling, simulations, experiments

This paper discusses modeling, simulations and experimental aspects of active aeroelastic control on aircraft wings by using Synthetic Jet Actuators (SJAs). SJAs, a particular class of zero-net mass-flux actuators, have shown very promising results in numerous aeronautical applications, such as boundary layer control and delay of flow separation...

Status of Wake Vortex Alleviation in the Framework of European Collaboration: Validation Using Tests and CFD Results

This document provides a synthesis of recent research studies that have been conducted in the last decade within several European projects from the 5th and 6th Framework Programmes. All these studies aimed at a better characterization of aircraft wake vortices and then at their subsequent control. In the latter case, the goal is to minimize the...

A perspective of mathematical simulation and optimization techniques in computer aided design

The central issue discussed in this paper is how a designer may profit from the use of mathematical simulation and optimization techniques. These techniques can be useful tools to support the designer in solving his design problem. The place and the potential of these techniques in the design process, as well as their use by the designer, are...

Accuracy of attitude control systems for satellites using double gimballed momentum wheels