The Experts below are selected from a list of 306 Experts worldwide ranked by ideXlab platform
Francesco Ciampa - One of the best experts on this subject based on the ideXlab platform.
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characterisation of smart cfrp composites with embedded pzt transducers for nonlinear Ultrasonic Applications
Composite Structures, 2018Co-Authors: Christos Andreades, Pooya Mahmoodi, Francesco CiampaAbstract:Embedded piezoelectric lead zirconate titanate (PZT) transducers in carbon fibre reinforced plastic (CFRP) composites are typically electrically insulated by interlaying materials such as polyimide Kapton films between the PZT and the laminate ply. However, the presence of polymeric films may cause debonding at the layer interface, thus reducing the structural performance. This paper proposes an alternative insulation technique in which PZTs are covered by a thin patch of woven E-glass fibre fabric for enhanced adhesion with the surrounding epoxy matrix. An analysis of variance on experimental test results showed that the compressive, flexural and interlaminar shear strengths of plain CFRP specimens were equal to the means of the smart CFRP composite (0.41 < p-value < 0.58), but significantly higher than those of Kapton specimens (0.0001< p-value < 0.05). Moreover, a post-test fractographic analysis indicated that damage opening in Kapton specimens was significantly larger (p-value = 0.03) than that in plain specimens. Brooming failure compression was also the same for the smart CFRP composite and plain samples, whereas Kapton specimens failed by through-thickness shear. Finally, nonlinear Ultrasonic experiments were conducted on CFRP laminates with artificial in-plane delamination using glass fibre insulated PZTs. Remarkably, the effect of second harmonic generation was found to be nearly two times higher than conventionally surface-bonded PZTs.
Vincent Laude - One of the best experts on this subject based on the ideXlab platform.
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Three-dimensional phononic crystal with ultra-wide bandgap at megahertz frequencies
Applied Physics Letters, 2021Co-Authors: Julio Andrés Iglesias Martinez, Johnny Moughames, Gwenn Ulliac, Muamer Kadic, Vincent LaudeAbstract:Phononic crystals have attracted wide attention in diverse scientific communities due to their ability to efficiently reflect, focus, and guide acoustic and elastic waves. Their use in Ultrasonic Applications such as medical imaging, however, remains elusive since three-dimensional phononic crystals with lattice constants in the range of hundreds of micrometers are required to operate with MHz ultrasound, smaller than what most additive manufacturing solutions can provide. This work presents a three-dimensional phononic crystal with a cubic symmetry having an experimental ultra-wide complete bandgap extending from 0.6 MHz to 7.5 MHz. Crystal specimens are manufactured using two-photon lithography at the microscale, with a lattice constant of 300 μm, and are characterized using heterodyne interferometry.
Christos Andreades - One of the best experts on this subject based on the ideXlab platform.
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characterisation of smart cfrp composites with embedded pzt transducers for nonlinear Ultrasonic Applications
Composite Structures, 2018Co-Authors: Christos Andreades, Pooya Mahmoodi, Francesco CiampaAbstract:Embedded piezoelectric lead zirconate titanate (PZT) transducers in carbon fibre reinforced plastic (CFRP) composites are typically electrically insulated by interlaying materials such as polyimide Kapton films between the PZT and the laminate ply. However, the presence of polymeric films may cause debonding at the layer interface, thus reducing the structural performance. This paper proposes an alternative insulation technique in which PZTs are covered by a thin patch of woven E-glass fibre fabric for enhanced adhesion with the surrounding epoxy matrix. An analysis of variance on experimental test results showed that the compressive, flexural and interlaminar shear strengths of plain CFRP specimens were equal to the means of the smart CFRP composite (0.41 < p-value < 0.58), but significantly higher than those of Kapton specimens (0.0001< p-value < 0.05). Moreover, a post-test fractographic analysis indicated that damage opening in Kapton specimens was significantly larger (p-value = 0.03) than that in plain specimens. Brooming failure compression was also the same for the smart CFRP composite and plain samples, whereas Kapton specimens failed by through-thickness shear. Finally, nonlinear Ultrasonic experiments were conducted on CFRP laminates with artificial in-plane delamination using glass fibre insulated PZTs. Remarkably, the effect of second harmonic generation was found to be nearly two times higher than conventionally surface-bonded PZTs.
Julio Andrés Iglesias Martinez - One of the best experts on this subject based on the ideXlab platform.
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Three-dimensional phononic crystal with ultra-wide bandgap at megahertz frequencies
Applied Physics Letters, 2021Co-Authors: Julio Andrés Iglesias Martinez, Johnny Moughames, Gwenn Ulliac, Muamer Kadic, Vincent LaudeAbstract:Phononic crystals have attracted wide attention in diverse scientific communities due to their ability to efficiently reflect, focus, and guide acoustic and elastic waves. Their use in Ultrasonic Applications such as medical imaging, however, remains elusive since three-dimensional phononic crystals with lattice constants in the range of hundreds of micrometers are required to operate with MHz ultrasound, smaller than what most additive manufacturing solutions can provide. This work presents a three-dimensional phononic crystal with a cubic symmetry having an experimental ultra-wide complete bandgap extending from 0.6 MHz to 7.5 MHz. Crystal specimens are manufactured using two-photon lithography at the microscale, with a lattice constant of 300 μm, and are characterized using heterodyne interferometry.
Pooya Mahmoodi - One of the best experts on this subject based on the ideXlab platform.
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characterisation of smart cfrp composites with embedded pzt transducers for nonlinear Ultrasonic Applications
Composite Structures, 2018Co-Authors: Christos Andreades, Pooya Mahmoodi, Francesco CiampaAbstract:Embedded piezoelectric lead zirconate titanate (PZT) transducers in carbon fibre reinforced plastic (CFRP) composites are typically electrically insulated by interlaying materials such as polyimide Kapton films between the PZT and the laminate ply. However, the presence of polymeric films may cause debonding at the layer interface, thus reducing the structural performance. This paper proposes an alternative insulation technique in which PZTs are covered by a thin patch of woven E-glass fibre fabric for enhanced adhesion with the surrounding epoxy matrix. An analysis of variance on experimental test results showed that the compressive, flexural and interlaminar shear strengths of plain CFRP specimens were equal to the means of the smart CFRP composite (0.41 < p-value < 0.58), but significantly higher than those of Kapton specimens (0.0001< p-value < 0.05). Moreover, a post-test fractographic analysis indicated that damage opening in Kapton specimens was significantly larger (p-value = 0.03) than that in plain specimens. Brooming failure compression was also the same for the smart CFRP composite and plain samples, whereas Kapton specimens failed by through-thickness shear. Finally, nonlinear Ultrasonic experiments were conducted on CFRP laminates with artificial in-plane delamination using glass fibre insulated PZTs. Remarkably, the effect of second harmonic generation was found to be nearly two times higher than conventionally surface-bonded PZTs.
