Domain
Categories
Viscoelastic properties of the ferret brain measured in vivo at multiple frequencies by magnetic resonance elastography
19 June 2023
Characterization of the dynamic mechanical behavior of brain tissue is essential for understanding and simulating the mechanisms of traumatic brain injury (TBI). Changes in mechanical properties may also reflect changes in the brain due to aging or disease. In this study, we used magnetic resonance elastography (MRE) to measure the viscoelastic properties of ferret brain tissue in vivo.
Voice coil actuators for two MTG instruments
19 June 2023
While Cedrat Technologies has been active in space for more than 20 years with piezoelectric mechanisms, we have also been increasingly involved over the last few years in the development of magnetic actuators for space projects. In this paper, a focus is made on the case of magnetic actuators that are developed in the frame of the Meteosat Third Generation (MTG) project. The first one is the Scan Assembly (SCA) actuated by Rotating Voice Coil Motors (RVCM) for the East/West (E/W) axes and the North/South (N/S) axes developed in collaboration with Sener and the second one is the Voice Coil Motor (VCM) developed in collaboration with CSEM for the Corner Cube Mechanism (CCM)
Wind-tunnel tests of a helicopter rotor with active flaps
19 June 2023
Within the frame of a project called DTP RPA (Développement Technique Probatoire Rotor à Pale Active), also known as Active Blade Concept, carried out in cooperation between ONERA, Eurocopter, DLR and Eurocopter Deutschland, a four-bladed Mach-scaled rotor was tested in December 2005 in ONERA S1 Modane wind-tunnel. The main objective of this test was to validate the concept of using active flaps located on the trailing edge of the blades of the main rotor of a helicopter to decrease the vibration level generated by this rotor.
Robustness of SHM techniques based on lamb waves
19 June 2023
Required improvements of piezoelectric elements actuation and measurement system efficiency and robustness are introduced as a critical feature for structural health monitoring (SHM) applications. An electronic module (Lamb wave detection system: LWDS) allowing to use each piezoelectric element in an array either in emission or reception mode is presented. The high commutation rate between these two states, for each transducer separately, is a key enhancement for SHM methods. The robustness of the sensor integration is also studied considering the patches size and bonding method. Coupled dispersion curve are introduced Comparison of FEM simulation and experiments of the piezo-electric coupling are presented. This work takes part of the H2020 REMAP project about adaptive aircraft maintenance planning.
XY200M a new design of piezo stage
9 January 2002
The XY200M is an XY piezo stage coming from CEDRAT TECHNOLOGIES lab and which was newly designed according to space needs defined with CNES (the French space agency). This XY stage benefi ts from the heritage of a former XY stage
developed for ESA (European Space Agency) in the frame of Rosetta / Midas space mission which will launch in the beginning of 2003. It is based on two pairs of APA200M, Amplifi ed Piezo Actuators displaying 200 µm of stroke each, arranged in cross configuration around a central ring.
Experimental assesment and further development of amplified piezo actuators for active flap devices
6 January 2002
RPA (Rotor à Pales Actives) Franco-German project was launched three years ago to study the possible benefits of implementing active trailing edge flaps on a helicopter main rotor. The main expected effects concern the decrease of BVI noise in descent flight and the improvement of the dynamic behaviour of the rotor throughout the largest possible flight domain. The technological solution adopted to deflect the flap of an 1/3rd scale rotor demonstrator, uses an off-the-shelf elliptic amplified actuator, from Cedrat Recherche Company, driving an innovative patented mechanism.
