Publications
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Piezo-composite patches applied to the detection of defects using lamb wave focusing
19 June 2023
Ultrasonic-based SHM (Structural Health Monitoring) applications usually rely on the use of piezo-electric patches to emit and receive ultrasonic surface acoustic waves. The principle is to study the propagation of the waves through a structure to assess its health. Because of the elevated number of echoes and possible modes of propagation of the acoustic waves within the structure, those applications suffer from a burden of signal processing. This paper presents a composite piezo-electric patch and its electronics that were designed and successfully tested for reducing the complexity of the SHM detection schemes.
Piezo-composite transducer for mode and direction selectivity of Lamb waves
19 June 2023
Ultrasonic-based SHM (Structural Health Monitoring) applications commonly rely on the use of piezo-electric patches to emit and receive ultrasonic waves. The objective is to study the propagation of the waves through a structure to assess its structural integrity. Because of the elevated number of echoes and possible modes of propagation of the waves within the structure, those applications suffer from a burden of signal processing. This paper presents a composite piezo-electric patch that was designed and successfully tested for reducing the complexity of the SHM detection schemes by selecting the mode and direction of the Lamb waves received. The piezo-composite is composed of a row of eight independent ceramic pillars separated with polymer, so it is a 1-D matrix of independent piezo-patches. Used with adequate electronics and signal processing, it was shown that it allowed selecting the direction and the mode of the Lamb waves.
Piezoelectric Actuator for precise and fast Oval Pistons manufacturing
19 June 2023
Piezoelectric Actuator and related driving & control electronic for precise and fast «Oval Pistons» manufacturing Oval pistons are used in all automotive industry. Every vehicle, motorbike, car and truck uses oval pistons. The reason is that pistons in these vehicles are working in very hot environment and as a consequence, the external shape deformation induced thermal growth of the piston is compensated by these «ovalities» (oval shapes).
Point Ahead Mechanism for Deep Space Optical Communication Development of a New Piezo-Based Fine Steering Mirror
19 June 2023
The purpose of this paper is to present the development of a novel tip-tilt mechanism, with integrated optics, designed for the JPL Deep Space Optical Communication (DSOC) module of the upcoming Psyche mission (2022 launch). This paper presents the design, assembly and tests of the produced models. Regarding the design phase, an emphasis was put on the mirror calculations to ensure that the required flatness would be maintained after integration, and that the part would withstand the thermal/mechanical environment. The actual optical measurements performed after assembly are also presented. The qualification results for a new alpha-case removal process for titanium parts are presented. Tests results are especially interesting
regarding the temperature behavior of the mechanism, impact on the stroke, and strain gage sensor feedback.
NASA ARC Novel sample handling for XRD analysis
19 June 2023
Sample preparation and sample handling are among the most critical operations associated with X-ray diffraction (XRD) analysis. These operations require attention in a laboratory environment, but they become a major constraint in the deployment of XRD instruments for robotic planetary exploration. We are developing a novel sample handling system that dramatically relaxes the constraints on sample preparation by allowing characterization of coarsegrained material that would normally be impossible to analyze with conventional powder-XRD techniques.
New actuators for aircraft, space and military applications
19 June 2023
Actuation is used in all vehicles (aircraft, spacecraft, ground vehicles, etc) to control the position and/or attitude of the vehicle, and also to deploy or retract equipment, particularly for embedded optic instruments (cameras, telescopes). As such, the actuation is a safety critical system, particularly when humans could be catastrophically affected by failures within the system. Applications for actuation are flight controls, landing gear, rotors, suspension, antennae steering, valves, scanning, positioning using hydraulic, electromechanical, magnetic and piezo actuators. In aircraft there is a common goal to reduce the number of hydraulic actuators in vehicles and eventually to replace them completely by electric actuators.
