The influence of tensile stress on inductively coupled piezoceramic sensors embedded in fibre-reinforced plastics

This article demonstrates that embedded piezoelectric sensors can survive loads much higher than predicted by their material properties. It shows the potential for piezoceramic sensors to estimate structural loads when embedded in composites. To show this, embedded sensors were subjected to stresses and strains which were significantly greater than the recommended operating limits of their piezoceramic constituents. A novel data acquisition method enabled ultrasonic guided wave measurements to be recorded wirelessly from the embedded transducers, key to minimising the impact of embedded transducers. The data recorded by the piezoceramic transducers exhibited a reversible load dependence, with the measurements returning to the stress-free values upon removal of the applied load. The guided wave measurements recorded by transducers embedded in glass fibre–reinforced composites showed no degradation after being subjected to tensile strains of 1.07%. When embedded in a carbon fibre–reinforced plastic sample which was loaded to failure, the transducers remained operational; however, sensor performance was shown to be degraded after being subjected to tensile stresses as high as 606 MPa. This offers the potential to build sensors to characterise overload in a component.

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Measurement of velocity and attenuation of ultrasonic guided wave for real-time estimation of cure-dependent anisotropic viscoelastic properties of carbon fiber-reinforced plastics

Ultrasonics ◽

10.1016/j.ultras.2019.105952 ◽

2019 ◽

Vol 99 ◽

pp. 105952 ◽

Cited By ~ 3

Author(s):

Koichi Mizukami ◽

Takahiro Ikeda ◽

Keiji Ogi

Keyword(s):

Carbon Fiber ◽

Real Time ◽

Viscoelastic Properties ◽

Time Estimation ◽

Guided Wave ◽

Carbon Fiber Reinforced Plastics ◽

Reinforced Plastics ◽

Ultrasonic Guided Wave ◽

Real Time Estimation ◽

Fiber Reinforced Plastics

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Effect of Laminate Configurations on Impact Properties of GFRP Composite in Seawater

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.7-8.223 ◽

2007 ◽

Vol 7-8 ◽

pp. 223-227

Author(s):

S.K. Srivastava ◽

I.P. Singh

Keyword(s):

Impact Properties ◽

Specific Strength ◽

Reinforced Plastics ◽

Marine Structure ◽

Hybrid Laminates ◽

Glass Fibre Reinforced ◽

Important Field ◽

Strength And Stiffness ◽

Transfer Moulding ◽

The Impact

Hybrid laminates of glass fibre reinforced plastics (GFRP) are being increasingly used for marine structures under multidirectional loadings, due to their anisotropic behavior, corrosion resistance, high specific strength and stiffness. Therefore appropriate laminate configuration for marine environment applications is an important field of study. Five types of fibre epoxy laminates configurations, resulting from different combinations of three layers of chopped strand mats (CSM) and woven roving (WR) were fabricated using the vacuum resin transfer moulding (VRTM) technique. These were investigated for the effect of seawater on its impact properties. The results showed a significant reduction in the impact strength in all types of wet specimens. This behavior may be attributed to penetration of water molecules in the composites. The impact properties of hybrid laminates using a mixture of CSM and WR were found to be better than combination of laminates comprising only CSM and WR under both dry and wet conditions for marine structure.

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Ultrasonic guided wave-based debond identification in a GFRP plate with L-stiffener

Smart Materials and Structures ◽

10.1088/1361-665x/ac3a97 ◽

2021 ◽

Author(s):

Kaleeswaran Balasubramaniam ◽

Shirsendu Sikdar ◽

Tomasz Wandowski ◽

Pawel M Malinowski

Keyword(s):

Laser Doppler Vibrometer ◽

Guided Wave ◽

Composite Panel ◽

Size Estimation ◽

Ultrasonic Guided Wave ◽

Point Analysis ◽

Glass Fibre Reinforced Polymer ◽

Depth Analysis ◽

Fibre Reinforced Polymer ◽

Glass Fibre Reinforced

Abstract This paper presents a robust assessment of debond in a glass fibre-reinforced polymer composite structure with L-stiffener attachment. Towards this, the ultrasonic guided wave (GW) propagation based laboratory experiments have been carried out on a stiffened composite panel with piezoelectric transducers (PZT) for the excitation of GWs and a scanning laser Doppler vibrometer (SLDV) for sensing the GW propagation. To study the changes caused by the stiffener and debond a signal processing based multi-point analysis has been carried out. The proposed methodology consists of two steps. Step 1 using the full wavefield root mean square energy map-based approach to check the presence of debond. Step 2 using point-wise measurements to study debond localization and size estimation using a baseline free signal coefficient difference algorithm (SCDA). The proposed processing approaches are applied for an in-depth analysis of the experimental signals that provide information about the interaction of GWs with stiffener and debond. The mentioned approaches take advantage of the asymmetry caused by the damage. For the applied SCDA methodology there is no need for full-wavefield measurements, healthy case measurements, as only a few measurement points can be enough for the assessment of stiffener debond in such structures.

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Elemental status of the adult able-bodied population of the Republic of Buryatia

Russian Journal of Occupational Health and Industrial Ecology ◽

10.31089/1026-9428-2019-59-5-308-313 ◽

2019 ◽

pp. 308-313

Author(s):

Inna Yu. Tarmaeva ◽

Anatoliy V. Skalny ◽

Olga G. Bogdanova ◽

Andrey R. Grabeklis ◽

Alexandr I. Belykh

Keyword(s):

Inductively Coupled Plasma ◽

Chemical Elements ◽

Federal District ◽

Significant Degree ◽

Electrolyte Imbalance ◽

Scientific Development ◽

Inductively Coupled ◽

Elemental Status ◽

The Republic ◽

The Impact

Introduction.The study of the elemental status of the population of individual regions of the Russian Federation with the purpose of scientific development and implementation of measures for elimination of revealed elementosis is a promising direction for preventive medicine.The aim of the studyis to study the elemental status of the adult able-bodied population of the Republic of Buryatia, which was part of the Siberian Federal district (SFD) until 2018.Materials and methods.The analysis was performed by inductively coupled plasma mass spectrometry (ICP-MS) on the basis of the accredited laboratory of “Center of biotic medicine”. (Moscow; ISO 9001: 2008 certificate 54Q10077 from 21.05.2010). The content of chemical elements in the hair of 130 adults (102 women and 28 men) aged 25–50 years was studied. This indicator serves as an indicator in assessing the impact of the environment on the human body. Methods of nonparametric statistics were used for mathematical processing of the data.Results.For women living in the Republic of Buryatia, the maximum values of Zn, increased levels of Cu, Li, Si were revealed; for men — the maximum values of Mg, Cr, Si, increased levels of P, Li, Se, V, Pb. Minimum values were found for P, Fe, V. Elemental status indicates a significant degree of prevalence of essential trace element deficiencies and electrolyte imbalance. The obtained data can be used as reference values for the content of chemical elements in the hair of adults living in the Republic of Buryatia.Conclusions:Elemental analysis of the population of the Republic of Buryatia indicates imbalances among the adult working-age population.

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