Jean-François Rouchon

Analytical modeling for the design of a piezoelectric rotating-mode motor

This paper deals with the analytical modeling of a rotating-mode motor. The modeling, based on an equivalent electric circuit, is established by using geometrical and electromechanical parameters for the different parts of the motor. It gives electromechanical characteristics and other useful values for motor design. Numerical simulations and measurements from a real transducer validate the analysis.

A hybrid morphing NACA4412 airfoil concept

This paper details the design and development of a hybrid actuator system combining surface actuated Shape memory alloys (SMAs) and trailing-edge Macro fibre composites (MFCs) for a NACA 4412 airfoil. This design allows both for a high-frequent (≈ 100 Hz) low-displacement actuation as well as a low-frequent large-displacement actuation. The design of the actuator system is highlighted, the simulation model is described and the test-setup is illustrated. Preliminary results are promising regarding the control of the desired lift.

A combined smart-materials approach for next-generation airfoils

This article will present a morphing wing actuated using both surface embedded Shape memory alloys (SMAs) and trailing edge Macro-fiber composites (MFCs). This combination enables the airfoil to simultaneously achieve large scale deformations at low frequencies as well as rapid actuation with a limited amount of displacement. Thereby not only can the shape of the airfoil be optimized in function of the current mission profile but also the shear layer can be influenced. Each actuator is modelled using both a finite element and/or an analytical model and the results will be verified experimentally.

Identification of the mechanical properties of the skin by electromechanical impedance analysis of resonant piezoelectric actuator

This paper is devoted to the analysis and verification of developed piezoelectric sensor/actuator for measuring the mechanical properties of soft tissues, especially human skin. The key element of the measurement structure is an electromechanical system that uses both the reverse piezoelectric effect (vibration generation - stimulation of the tissues in the appropriate frequency range) and direct piezoelectric effect (system response registration). By analyzing the response of the piezoelectric sensor/actuator - an electromechanical signature of the tested tissue, it is possible to identify a series of mechanical quantities describing the tested object, such as stiffness, viscosity, Youngs modulus. An analytical approach is shown in order to establish a link between the electromechanical equivalent circuit obtained for a resonance frequency of the actuator and the calculations based on the Hertzs contact mechanics theory. A finite element method analysis is then presented in order to assess the performance of the chosen topology of piezoelectric sensor/actuator. Finally, the proposed method of impedance characterization is verified experimentally by a prototype of piezoelectric bimorph sensor/actuator.

Design, modelling and analysis of a new type of piezoelectric motor. Multicell piezoelectric motor

This paper describes a new type of piezoelectric motor. The results, obtained in the field of piezoelectric motors, have pointed out that these motors have potentially high possibilities in the future special applications. The research work presents the design, simulations and parameters of the piezoelectric motor with three rotation-mode actuators. The motor is characterized by a high power, relative high speed and torque. The motor consist of stator with few (minimum 3) rotating mode actuators. The purpose of those efforts was to develop a new actuator dedicated for the embedded applications.

Electroactive materials : from piezomotors to electroactive morphing

Electroactive materials concerns a wide variety of physical phenomena which plays today an important part in the research of novel electromechanical systems. The present article proposes a survey of the modern stakes of electrodynamics in this field, from physical processes to sophisticated electromechanical functions. The potential of the new technologies considered is evaluated through different examples of novel actuators which aim at meeting the increase of the performances or the expansion of required functionalities in the face of varied types of applications. Besides the development of new drives, recent investigations concerning the concept of electroactive morphing applied to air flow control are dealt with at the end of the article. The aim is first the quasi-static shape control of a large aircraft wing and second, the dynamic control of a turbulent boundary layer so as to reduce friction drag

An Experimental Platform for Surface Embedded SMAs in Morphing Applications

This article will address the modeling and control of surface embedded shape memory alloys (SMAs) for the camber modification of a hybrid morphing airfoil. An analytical model will be derived. The results of this models will be discussed and compared to the experiments. The advantages of this modeling approach will be highlighted and alternatives will be briefly revisited. This discussion will figure into the utility of these models in the sizing of a full scale prototype of a SMA actuated active trailing edge of an airfoil. Throughout this article the prototype specifications are detailed and the design choices will be discussed. Performance improvements stemming from the inherent nature of the SMAs will be analyzed. It will be shown in this article that through the use of forced convection the overall cycle time can be reduced.

On the multidisciplinary control and sensing of a smart hybrid morphing wing

Morphing wing technology is of great interest for improving the aerodynamic performance of future aircraft. A morphing wing prototype using both surface embedded Shape Memory Alloys (SMA) and piezoelectric macro fiber composite (MFC) actuators has been designed for wind tunnel experiments. This smart wing is a mechatronic system that contains embedded sensors to measure the surrounding flow and control the actuators. This article will focus on the control of the cambering system which is achieved using a group of nested control loops as well as on the perspective of a novel control strategy using in-situ temperature measurements. It will be shown that by exploiting the inherent hysteretic properties of the SMAs cambering a significant reduction in power consumption is possible by appropriately tailoring the control strategy. Furthermore, by comparing the post-processed pressure signals recorded during the wind tunnel experiments to the aerodynamic performance gains a perspective for a novel in-situ control will be shown.

A new prototype of piezoelectric bending resonant transducer for analysis of soft tissues properties

A new prototype of piezoelectric bending resonant transducer for analysis of soft tissues properties