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Michelle Salvia

Bio: Michelle Salvia is an academic researcher from École centrale de Lyon. The author has contributed to research in topics: Epoxy & Charpy impact test. The author has an hindex of 13, co-authored 53 publications receiving 538 citations.


Papers
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Journal ArticleDOI
TL;DR: In this article, a textile reinforced concrete panels including microencapsulated phase change materials (PCMs) in a variety of mix designs was used for improving energy efficiency in buildings.

78 citations

Journal ArticleDOI
01 Jan 2014-Scanning
TL;DR: The experimental results indicated the sandblasting process duration necessary to reach a morphological steady state, and a new topographic parameter Sr, combining the surface amplitude and the summit density distribution, is proposed as a factor well-correlated with wettability characteristics.
Abstract: Summary PolyEtherEtherKetone (PEEK) is an advanced high-performance thermoplastic polymer, and its composites are used extensively in the aeronautical industry. This paper presents an experimental approach to determine the role of sandblasting treatment on surface morphology modifications of PEEK and its composites, with the aim of developing a topographic characterization in order to propose pertinent parameters that correlate with contact angles from wettability measurement. Sandblasting (fine abrasive particle projection) was selected as the surface treatment, in order to obtain various morphologically quasi-isotropic surfaces. Two surface metrological approaches to topographical characterization were used to correlate the wettability behavior with the surface roughness parameters, the first based on 2D profile analysis and the second on 3D topography analysis. Two different unreinforced grades of PEEK and four composites: discontinuous carbon fiber or glass fiber-reinforced, oriented, and unoriented, were studied. The experimental results indicated the sandblasting process duration necessary to reach a morphological steady state. It was stated that one of the pertinent parameters is the mean slope of roughness motif in 2D profile characterization, as confirmed by previous findings for anisotropic morphologies. However, for all cases, a new topographic parameter Sr, combining the surface amplitude and the summit density distribution, is proposed as a factor well-correlated with wettability characteristics. SCANNING 36:64–75, 2014. © 2013 Wiley Periodicals, Inc.

63 citations

Journal ArticleDOI
TL;DR: In this paper, the effect of sheet electron beam irradiation on the impact value of GFRPs mainly depends on the ductility enhancement of the GFRP. And the irradiation, applied as a short-time treatment at room temperature, enhances the average impact value at every fracture probability, and also enhances the reliability indicated by the minimum impact value, as well as the Weibull coefficient.
Abstract: Glass fiber reinforced polymers GFRPs are increasingly being applied as structural materials with their advantages of light weight and high strength in the fields of aerospace engineering and rapid transport engineering. To strengthen the GFRPs, sheet electron beam (EB) irradiation under low potential has been performed homogeneously. Effects of EB-irradiation on Charpy impact value of GFRPs have been studied. The irradiation, applied as a short-time treatment at room temperature, enhances the impact value of GFRPs at every fracture probability. The effect of EB-irradiation on the impact value of GFRPs mainly depends on the ductility enhancement of the GFRPs. EB-irradiation also enhances the reliability indicated by the minimum impact value (a s ), as well as the Weibull coefficient.

38 citations

Journal ArticleDOI
TL;DR: In this article, the effects of sheet electron beam irradiation under low potential on the Charpy impact value of carbon fiber reinforced polymer (CFRP) have been investigated, which depends on the enhancement of interfacial force, as well as the strengthening of carbon fibre and polymer.
Abstract: Effects of sheet electron beam irradiation under low potential on the Charpy impact value of carbon fiber reinforced polymer (CFRP) have been investigated. The irradiation, which is one of short-time treatments, enhances the impact value of CFRP. It probably depends on the enhancement of interfacial force, as well as the strengthening of carbon fiber and polymer.

37 citations

Journal ArticleDOI
TL;DR: In this article, a fiber-optic sensor was used to measure the angular distribution of light transmitted through an optical fibre inside the cured polymer. But the sensitivity to the refractive index was tested with aniline (n = 1.58) mixed with various concentrations of toluene (n= 1.50).
Abstract: Real-time, in situ monitoring for quality control of the polymer cure process is of great interest. In fact, high-performance composites, made with polymer matrixes, are used extensively in high-tech areas, such as the aircraft, space and automobile industries. In particular, epoxy resin reinforced with fibre is a system with good mechanical properties and low density. In this paper, a fibre-optic sensor to monitor the cure of an epoxy resin is studied. Optical fibres are, in fact, compatible with the reinforcing fibre in laminate composites. This sensor is based on the measurement of the angular distribution of light transmitted through an optical fibre inside the cured polymer. The light guiding properties of this sensor are linked to the difference between the refractive index of the core and that of the cladding. So, by partially removing the cladding and placing a sample of curing epoxy around the stripped region, it is possible to monitor the extent of the cure. In fact, the refractive index of the DGEBA/amine system varies from 1.54 to 1.58, mainly due to the increase in density during the cure. For manipulation, an experimental fibre made of special glass was prepared so as to have a high refractive index core (n = 1.62). The sensitivity to the refractive index was tested with aniline (n = 1.58) mixed with various concentrations of toluene (n = 1.50). The response of the sensor to this liquid test showed that it would be possible to measure the refractive index in the index range of epoxy during cure. Tests with an epoxy system were also performed. In order to understand the angular distribution of the transmitted light, a model based on geometrical optics was developed using the reflection coefficient of the optical ray on a boundary between two dielectrics. This allowed us to obtain real and imaginary parts of the cladding refractive index, thus the cross-link density during the epoxy cure can be monitored with a single fibre-optic sensor.

33 citations


Cited by
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Journal ArticleDOI
TL;DR: A comprehensive review of literature on bio-fiber reinforced composites is presented in this paper, where the overall characteristics of reinforcing fibers used in biocomposites, including source, type, structure, composition, as well as mechanical properties, are reviewed.

3,074 citations

Journal ArticleDOI
TL;DR: Data normalization is a procedure to normalize datasets, so that signal changes caused by operational and environmental variations of the system can be separated from structural changes of interest, such as structural deterioration or degradation.
Abstract: Stated in its most basic form, the objective of structural health monitoring is to ascertain if damage is present or not based on measured dynamic or static characteristics of a system to be monitored. In reality, structures are subject to changing environmental and operational conditions that affect measured signals, and these ambient variations of the system can often mask subtle changes in the system’s vibration signal caused by damage. Data normalization is a procedure to normalize datasets, so that signal changes caused by operational and environmental variations of the system can be separated from structural changes of interest, such as structural deterioration or degradation. This paper first reviews the effects of environmental and operational variations on real structures as reported in the literature. Then, this paper presents research progresses that have been made in the area of data normalization.

685 citations

Journal ArticleDOI
TL;DR: In this article, a wavelet-based signal processing technique is developed and combined with an active sensing system to produce a near-real-time, online monitoring system for composite structures, where a layer of piezoelectric patches is used to generate an input signal with a specific wavelet waveform and to measure response signals.
Abstract: In this paper a signal processing technique is developed to detect delamination on composite structures. In particular, a wavelet-based signal processing technique is developed and combined with an active sensing system to produce a near-real-time, online monitoring system for composite structures. A layer of piezoelectric patches is used to generate an input signal with a specific wavelet waveform and to measure response signals. Then, the response signals are processed by a wavelet transform to extract damage-sensitive features from the original signals. The applicability of the proposed method to delamination identification has been demonstrated by experimental studies of a composite plate under varying temperature and boundary conditions.

313 citations

Journal ArticleDOI
TL;DR: In this article, the effect of thermoplastic modification and fibre loading on the dynamic mechanical properties of the composites were also analyzed using dynamic mechanical analysis (DMA) and TGA.
Abstract: Poly(styrene-co-acrylonitrile) (SAN) was used to modify diglycidyl ether of bisphenol-A (DGEBA) type epoxy resin cured with diamino diphenyl sulfone (DDS) and the modified epoxy resin was used as the matrix for fibre reinforced composites (FRPs) in order to get improved mechanical and thermal properties. E-glass fibre was used as the fibre reinforcement. The morphology, dynamic mechanical and thermal characteristics of the systems were analyzed. Morphological analysis revealed heterogeneous dispersed morphology. There was good adhesion between the matrix polymer and the glass fibre. The dynamic moduli, mechanical loss and damping behaviour as a function of temperature of the systems were studied using dynamic mechanical analysis (DMA). DMA studies showed that DDS cured epoxy resin/SAN/glass fibre composite systems have two Tgs corresponding to epoxy rich and SAN rich phases. The effect of thermoplastic modification and fibre loading on the dynamic mechanical properties of the composites were also analyzed. Thermogravimetric analysis (TGA) revealed the superior thermal stability of composite system.

263 citations