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American Society for Testing and Materials

The versatile characteristic of epoxy and its diversity made it suitable for different industrial applications such as laminated circuit board, electronic component encapsulations, surface coatings, potting, fiber reinforcement, and adhesives. However, the pervasive applications in many high-performance field limited the epoxy use because of their delamination, low impact resistance, inherent brittleness, and fracture toughness behavior. The limitations of epoxy can be overcome by incorporation and modification before their industrial applications. Currently, modified epoxy resins are extensively used in fabrication of natural fiber-reinforced composites and in making its different industrial products because of their superior mechanical, thermal, and electrical properties. Present review article designed to be a comprehensive source of recent literature on epoxy structure, synthesis, modified epoxy, bio-epoxy resin, and its applications. This review article also aims to cover the recent advances in natur...

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Recent advances in epoxy resin, natural fiber-reinforced epoxy composites and their applications

Tomographic absorption spectroscopy for the study of gas dynamics and reactive flows

Interferometric hologram evaluation and real-time vibration analysis of diffuse objects

Advances, limitations and prospects of nondestructive testing and evaluation of thick composites and sandwich structures: A state-of-the-art review

This Letter presents a method for real-time 3D measurements based on three-color digital holographic interferometry. The optical setup is considerably simplified, since the reference beams are combined into a unique beam. A convolution algorithm allows the three monochrome images to be superposed to provide simultaneous full-field 3D measurements. Experimental results confirm the suitability of the proposed method.

Real-time three-sensitivity measurements based on three-color digital Fresnel holographic interferometry

Optical techniques are now broadly used in the field of experimental mechanics. The main advantages are they are non intrusive and no contact. Moreover optical techniques lead to full spatial resolution displacement maps enabling the computing of mechanical value also in high spatial resolution. For mesoscopic measurements, digital image correlation can be used. Digital holographic interferometry is well suited for quantitative measurement of very small displacement maps on the microscopic scale. This paper presents a detailed analysis so as to compare digital Fresnel holography and digital image-plane holography. The analysis is based on both theoretical and experimental analysis. Particularly, a theoretical analysis of the influence of the aperture and lens in the case of image-plane holography is proposed. Optimal filtering and image recovering conditions are thus established. Experimental results show the appropriateness of the theoretical analysis.

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Comparison between Digital Fresnel Holography and Digital Image-Plane Holography: The Role of the Imaging Aperture

This paper proposes a first attempt to visualize and analyze the vibrations induced by a bone-conduction device and propagating at the surface of the skin of a human face. The method is based on a new approach in a so-called quasi-time-averaging regime, resulting in the retrieval of the vibration amplitude and phase from a sequence of digital Fresnel holograms recorded with a high image rate. The design of the algorithm depends on the ratio between the exposure time and the vibration period. The results show the propagation of vibrations at the skin surface, and quantitative analysis is achieved by the proposed approach.

Evaluation of surface acoustic waves on the human skin using quasi-time-averaged digital Fresnel holograms

Dielectric analysis of the interfacial polarization of alkali treated woven flax fibers reinforced epoxy composites

This paper presents a reference-free metric for quantitative appraisal of de-noising algorithms for phase measurements in digital holography. In the literature, quality metrics are not self-contained because they require a noise-free reference phase fringe pattern in order to be computed. In practical situations, no exact phase is available to evaluate the quality of processing. In order to bypass such limitations, one needs a metric directly capable of providing information on how efficient the filtering is, without any help from any reference measurements and by only considering the measured available phase data. This paper presents a novel reference-free metric, called estimated phase error for quantitative appraisal of de-noising algorithms for noisy phase data processing. This metric is based on the computation of an estimator of the standard deviation of the phase error between data processed with an external algorithm and that from the evaluated algorithm. A benchmark, including 37 different de-noising algorithms, demonstrates that the proposed metric is capable of producing the same rankings as those obtained with classical metrics, requiring a reference phase. Application to phase data from mechanical testing demonstrates that the ranking obtained from experimental phase data is similar to that obtained during the benchmarking with simulated data.

Mayssa Karray

Papers

Real-time three-sensitivity measurements based on three-color digital Fresnel holographic interferometry

Comparison between Digital Fresnel Holography and Digital Image-Plane Holography: The Role of the Imaging Aperture

Evaluation of surface acoustic waves on the human skin using quasi-time-averaged digital Fresnel holograms

Dielectric analysis of the interfacial polarization of alkali treated woven flax fibers reinforced epoxy composites

Reference-free metric for quantitative noise appraisal in holographic phase measurements