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The document introduces the idea of interactional discrimination and puts it to test through two interlocking field experiments. As a first approximation, interactional discrimination covers part of the phenomena usually designated with the more informal label of “everyday discrimination”. It is also close to other more formal ideas such as “interpersonal discrimination”, “micro-aggresion” and “assault on self-worth”. The latter three ideas are predicated on an opposition between economic and non-economic outcomes of discrimination. In contrast, the defining feature of interactional discrimination is the specific context in which it occurs: a spatio-temporally bounded episode of social interaction. The two reported field experiments show that women who wear an Islamic headscarf in France are exposed to interactional discrimination on the part of men. The data indicate that in the course of a face-to-face engagement with a hijab-wearing woman, men avert gaze, and that on average this pattern of gaze aversion causes strong negative emotions or stress in the recipient. The study shows that stress represents a specific form of harm that interactional discrimination causes to women who wear the hijab in public. It is argued that pre-existing ideas of everyday discrimination, owing to their focus on the conceptual experience of indignity, are not well-suited for accommodating the often unreflective experience of stress.

International audience; A long-term structural health monitoring program started in 2000 with a seismometrical monitoring station installed in 44-storey ÒEdelweissî tower. Since then several high-rise residential buildings in Moscow were equipped with monitoring systems. The research includes both practical and scientific purposes. The practical one is to increase the structural safety by detecting anomalies in structural behaviour. The scientific one is to gain knowledge about the evolution of reinforced concrete structures stress-strain state during the construction and operation of buildings. The large amounts of data have been obtained using various types of equipment (seismometers, pressure cells, extensometers and vibrating wire strain gauges). Based on results it was possible to establish main factors that influence the stress-strain state of structures. The actual data was compared to simulation results and the most appropriate computer models were determined. The redistribution of stresses between parts of a construction turned out to be impossible to reproduce by means of finite element analysis in current software suites was found. Finally, a technique of long-term forecast of the stress-strain state of reinforced concrete structures was developed.

International audience; The possibility to deduce dynamic strains from acceleration measurements is investigated in this paper. The classic technique applied on beam-like structures which consists in using vertical accelerations to estimate longitudinal strains with a second order central finite difference is compared with two methods based on horizontal accelerations. Time domain responses of accelerometers and strain sensors installed on a simply supported beam are simulated, and the trains deduced from accelerations are compared with the real strains. The possibility of locating damage with the mode shape obtained with estimated strains is also addressed.

International audience; Structural Health Management strategies usually involve monitoring complex components, during their working life. Carbon fiber reinforced polymer components are becoming more and more used, throughout the structural engineering fields, because of their superior mechanical properties. Moreover, due to their construction, these materials open the path for new Òsmartî components, with integrated sensors and monitoring capabilities. Flexible circuits are essential in this context. In order to adapt to complex geometries, sensors and their connectivity have to be flexible and as un-intrusive as possible. Following previous work, aimed at inserting sensors with flexible connectivity in between the sheets of carbon fibers, we conceived and implemented a reconfigurable acquisition system that can be easily adapted to perform strain measurements in various EM5 noise conditions. This paper presents a comparison between three circuits dedicated to strain measurement using a commercial strain gauge and flexible connectivity on Kapton2. The first circuit consists of a classic Wheatstone bridge under continuous voltage. The second uses the synchronous detection principle with classic circuits and functions. The third innovates upon the synchronous detection principle by implementing several functions in a reprogrammable analog chip called FPAA (Filed Programmable Analog Array). The analysis of these circuits shows the added value of using reconfigurable devices with flexible connectivity and sensors in order to provide a universal solution for the monitoring of complex components.

International audience; This study deals with the development of an innovative weigh-in-motion (WIM) sensor. An electrically conductive nanocomposite material based on a mixture of graphene supported on sepiolite and carbon nanotubes was developed. Deposited on bituminous mix with copper electrodes, it is used as a force sensor. We detail the sensor fabrication process and study its sensitivity to a compressive force.

International audience; The present contribution investigates the piezoelectric performance of novel ceramic modules for SHM applications. The multilayer technique is used to embed piezoceramic plates into an encasement made of low temperature cofired ceramics, including electric wiring and electronics. With the help of finite element analyses, the piezoelectric properties are derived from static bending experiments using large signal electrical loads. A significantly increased piezoelectric coupling is found for the embedded piezoelectric elements compared to single elements. This finding is explained by the particular stress state in the embedded piezoelectric element due to the fabrication process.

International audience; The VIC method consists in finding the analytical contour by fitting the boundary of the objet in the picture as best as possible. It has been used for shape measurement of an inflatable beam submitted to a transverse wind in the CSTB wind tunnel in Nantes. The principle and the main equations of the method are recalled. The originality of this study is that the equation of the contour is deduced from the analytical expression of the deformation of an inflatable beam under a distributed constant (aerodynamic) load. This acts as a powerful mechanical-based filter and leads straightforwardly to the researched mechanical properties of the textile membrane.

International audience; This work proposes a new type of low-cost strain sensor, based on piezoresistive carbon nanotube (CNT) network deposited on a flexible substrate. Experimental results show that the strain can be reliably measured thanks to the highly linear piezoresistive behaviour of the CNT network and thanks to temperature compensation capabilities. Moreover, the experimental results show the capability of measuring multiple loading cycles. The performance and the range of sensitivity of the device, suggest possible usage in the domain of embedded monitoring, in particular the detection of micro-strain and micro-cracking in concrete. In order to target this domain, a wireless RFID solution to embed the sensor into concrete is provided.

This research studies the performance of a battery-free wireless antenna sensor for measuring crack propagation. In our previous work, a battery-free folded patch antenna was designed for wireless strain and crack sensing. When experiencing deformation, the antenna shape changes, causing shift in electromagnetic resonance frequency of the antenna. The wireless interrogation system utilizes the principle of electromagnetic backscattering and adopts off-the-shelf 900MHz radiofrequency identification (RFID) technology. Following the same sensing mechanism, a slotted patch antenna sensor of smaller size is designed. The antenna detours surface current using slot patterns, so that the effective electrical length is kept similar as previous folded patch antenna. As a result, the sensor footprint is reduced and the antenna resonance frequency is maintained within 900MHz RFID band. To validate the sensor performance for crack sensing, a fatigue crack experiment is conducted on a steel compact-tension specimen. A slotted patch antenna sensor is installed at the center of the A36 steel specimen. For wireless interrogation, a Yagi reader antenna is placed 36 in. away from the antenna sensor to wirelessly measure the resonance frequency shift of the antenna sensor. The measurement is taken after every 10,000 loading cycles, till the specimen fails. Meanwhile, the length and width of the fatigue crack are also recorded. Finally, the resonance frequency shift of the antenna sensor is correlated with crack length and width at each loading stage.

Structural health monitoring solutions gain in importance not only as part of the ageing management of nuclear power plant components but also in the context of conventional power plants and renewables such as wind power plants. Consequently, lots of operators have to deal with demanding security requirements to ensure the safe operation of power plants and to cope with plant lifetime extension (PLEX) related issues. AREVA disposes of a long tradition in the development of structural health monitoring (SHM) solutions. Nuclear and conventional power plant applications require the qualified assessment of measured thermo-mechanical loads. The methodology is transferable to mechanical loading conditions such as those of wind energy plants. The core challenge is the identification and qualified processing of realistic load-time histories. In terms of the nuclear industry, the ageing management of power plant components is nowadays a main issue for all actors: states, regulatory agencies, operators, designers or suppliants. As regards fatigue assessment of nuclear components stringent safety standards imply the consideration of new parameters in the framework of the fatigue analysis process: new design fatigue curves, consideration of environmental fatigue (EAF) parameters and stratification effects. In this general context AREVA developed the integral approach AREVA Fatigue Concept (AFC) with new tools and methods in order to live up to operators expectations: Simplified Fatigue Estimation (SFE), Fast Fatigue Evaluation (FFE) and Detailed Fatigue Check (DFC). Based on real measured thermal loads and superposed mechanical loads the Fast Fatigue Evaluation (FFE) process allows a highly automated and reliable data processing.

International audience; In the framework of the FP7-project SMARTFIBER (http://www.smartfiber-fp7.eu/) an optical fibre prototype has been developed with a cladding diameter of approximately 60 µm. Draw Tower fibre Bragg gratings (DTG¬s) are inscribed in this fibre which show identical strain optic and thermo optic characteristics compared to the standard commercial available 125 µm version, moreover they show superb ultimate failure strain of more than 7%. This characteristic plays an important role when automatic fibre embedding processes are envisaged. In this paper, the developed 60 µm fibre prototypes are successfully been applied during automated fibre placement on prepreg material. The results of the calibration tests and of the strain evolution of the DTG¬ during automated fibre placement will be presented in this paper

International audience; The Structural Health Control (SHC) concept is a novel and overarching approach to monitor the strength of a structure online and in realtime over its lifecycle. In the center of the SHC approach is the structural analysis of the monitored part. It provides the information to identify structural parameters as damage indicators. With this information an optimized sensor layout can be defined to monitor the damage indicators in a smart way. The monitoring system is therefore referred as SmartSHM system. This article is about the experimental validation of the SmartSHM concept within the SHC approach. The SmartSHM system is tested at a simply supported thin plate under compressive loading close to ultimate load. In the post-buckling regime bending occurs which causes high tension stresses at the plateÕs surface despite of the compressive loading. These stresses can initiate a crack due to fatigue. Therefore these regions are monitored with a SmartSHM system. Cracks were initiated to prove the functionality of the proposed SHM concept.

International audience; We present a novel integration-driven approach to the design of multi-scale multi-physics sensors and systems. We implement this method to model, design, fabricate and characterize a thin, conformable low-cost impact detection sensor based on assemblies of piezoelectric GaN nanowires. When suitably assembled, the latter demonstrate a macroscale additivity of their nanoscale intrinsic properties, which enables to appeal to classical fabrication techniques and exploitable electronic readouts at the system level. We also exploit multi-level simulations to provide useful insights of adapted application-driven integration solutions for these new forms of sensors. We demonstrate the potential of such application-targeted, fully-integrated and modular systems to accommodate to the stringent requirements of structural health monitoring (SHM).

International audience; A method is introduced for the measurements of strain exploiting the interaction between ultrasound waves and characteristics of the insonified specimen. First, the response of obliquely incident harmonic waves to a deterministic surface roughness is utilized. Analysis of backscattered amplitudes in Bragg diffraction geometry then yields a measure for the in-plane strain field by mapping any shift in angular dependency. Secondly, the analysis of the reflection characteristics of normal incidence pulsed waves in frequency domain provides the out-of-plane normal strain field component, simply by tracking any change in the stimulation condition for a thickness resonance. As such, the developed method yields an absolute, contactless and single-sided mapping of a local 3D strain field, in which both sample preparation and alignment procedure are ubiquitous. The ultrasonic strain gauge is applicable to any material, though under the restriction that a deterministic surface roughness is present. Results are presented for cold-rolled DC06 steel samples onto which skin passing of the work rolls is applied. The samples have been mechanically loaded, introducing plastic strain levels ranging from 2% to 35%. The ultrasonically measured strains have been validated with other strain measurement techniques, yielding good agreement. As the ultrasonic strain gauge provides all three strain field components, we extracted Lankford ratios for the DC06 steel sheet at different applied plastic strain levels revealing a strain dependent plastic anisotropy of the DC06 steel.

This paper describes an implemented structural health monitoring (SHM) system based on Fibre Optic Bragg Grating (FOBG) sensors and standard resistance strain gauges (SGs) placed onto/into a stiffened carbon fibre-reinforced polymer (CFRP) fuselage panel. The role of the FOBG sensor system was to monitor the structural integrity of the reference, impacted and fatigued panels under compression loading. The FOBG and/or SG sensors were placed (embedded or bonded) at various locations into and/or onto the structure. The functionality of the SHM system was verified by experimental evaluation. The comparability and reliability of the results gained from the FOBG sensors and resistance strain gauges is discussed. This paper presents the key objectives from a European Union funded collaborative Project, inside the Clean Sky Joint Technology Initiative (CS JTI), investigating the SHM systems for CFRP fuselage stiffened panels based on fibre optic Bragg grating sensors for the Green Regional Aircraft Integrated Technology Demonstrator (GRA ITD).

International audience; This research paper presents the study of thermography and shearography to evaluate CFRP reinforcement of concrete structures. The study explores the strengths and weaknesses of both non-destructive-testing (NDT) methods. It will be shown that by coupling the methods, the detection is more reliable and the defect evaluation more thorough as both the thermal and thermo mechanical properties are tested. Once the core theoretical concept regarding both methods is presented, the viability is demonstrated in the experimentation part of this study. With the experimental results confirming the feasibility of the coupling of both methods, the numerical model conceived allow to better conduct analysis that are not otherwise possible with the experimental results.

In this work there have been investigated the potential usage of the CNT's as strain sensors for the structural health monitoring based on the spray coatings. Experimental work was performed on the metal and glass-reinforced composites. Multiwalled Carbon Nanotubes (MWCNTs) were mixed with different matrix materials (acrylic and epoxy) and then applied to the test material with the use of two techniques (screen printing and spray coating). Futhermore, sensors were investigated using SEM. Response of the sensors was measured due to the tensile test of the specimens..

International audience; This paper presents an inverse modeling technique using dynamic strain responses to identify the prestressed concrete beam parameters: the pretension in the cable and the prestress in the concrete. The direct problem corresponds to 2D elastodynamics equations. To get the beam parameters, we minimize a classical data misfit function using a gradient-like algorithm. A low-cost computation of the functional gradient is performed using the adjoint problem