Anisotropy of NEWS damage parameters in CFRP composite

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21230%2F16%3A00303739" target="_blank" >RIV/68407700:21230/16:00303739 - isvavai.cz</a>

Result on the web

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DOI - Digital Object Identifier

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Result language

angličtina

Original language name

Anisotropy of NEWS damage parameters in CFRP composite

Original language description

Nonlinear Elastic Wave Spectroscopy (NEWS) methods are broadly used in NDT as a highly effective means for detection of damage in various materials and structures. NEWS methods exploit the non-linear, amplitude dependent response of material to its acoustic interrogation. Variety of NEWS techniques provide sensitive detection of incipient damage like microcracks, delamination, weakening of adhesive bonds and corrosion. Their advantages consist not only in high sensitivity but also in the ability to detect defects smaller than the used wavelength, which is important in modern composite structures use. Suitable configurations of transducers enable also location of defective zones characterized by appropriate non-linear parameters obtained by NEWS techniques along different wave paths. In composites the correct evaluation of nonlinearity is often problematic. For that purpose we designed a multi-directional ultrasonic probe with 8 to 32 piezoelectric transducers multiplexed as transmitters and receivers. Their positions are free adjustable along directional lines and can be fixed in various configurations. A circular configuration around the center (span 50–300 mm) is most suitable for instantaneous anisotropy evaluation of wave celerity in selected region. All transducers are equipped with suction cups and resin shoes to ensure a constant coupling. The probe with frequency range 100–600 kHz is connected to the multichannel PXI system through multiplexer and preamplifiers. The probe was used to obtain patterns of wave celerity, attenuation, and nonlinearity parameters on CFRP plates, both intact and damaged by impact and artificial delamination. The probe can be applied not only to plates but also to curved surfaces. Three NEWS methods were applied: Time Reversal-NEWS, nonlinear wave modulation spectroscopy (NWMS), and scale subtraction method (SSM). Respecting material anisotropy contributes to more reliable determination and location of defects by NEWS methods.

Czech name

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Czech description

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Type

O - Miscellaneous

CEP classification

JI - Composite materials

OECD FORD branch

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Project

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Continuities

S - Specificky vyzkum na vysokych skolach

Publication year

2016

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů