scholarly journals Capabilities of Lock-in Thermography for Non-destructive Inspection of Fibre Reinforced Composites

2012 ◽  
Author(s):  
T. Ullmann ◽  
Y. Shi ◽  
R. Aoki
Keyword(s):  
Reinforced Composites ◽  
Lock In ◽  
Non Destructive ◽  
Fibre Reinforced Composites

scholarly journals Ultrasonic Non-Destructive  Testing of Fibre Reinforced  Composites

2021 ◽  
Author(s):  
◽  
Matthew Thomson
Keyword(s):  
Experimental Work ◽  
Rayleigh Waves ◽  
Ultrasonic Waves ◽  
Reinforced Composites ◽  
Surface Cracks ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Reinforced Composite ◽  
Non Destructive ◽  
Fibre Reinforced Composites

<p>This thesis focuses on the application of high frequency ultrasound as a tool for performing non-destructive testing for pultruded fibre reinforced composite (FRC) rods. These composite rods are popular in the manufacturing, construction and electrical industries due to their chemical, electrical and strength properties. Such FRCs are manufactured on automated production lines that operate day and night. Non-destructive testing techniques are desired to quickly and accurately detectmanufacturing flaws such as coating thickness irregularities and surface cracks. Layers and cracks can present as large changes in acoustic impedance and will strongly reflect ultrasonic waves. Combined with their low cost, east of use and absense of potentially harmful radiation, ultrasound has proven popular worldwide for Non-Destructive Testing. Finite Element Analysis (FEA) was employed to investigate the propagation of ultrasonic waves through layers of material to simulate a thickness measurement and the ability of ultrasound to measure thicknesses was proven. Experimental work was conducted on two fibre reinforced composite samples with varying thickness coatings of plastic and paint. The thickness was measured accurately using immersion transducers at 50MHz and a resolution of 20μm was attained through the use of matched filtering techniques. Surface acoustic waves, particularly Rayleigh waves were investigated using FEA techniques so that the generation, scattering and detection of such waves was understood. This lead to the development of methods for detecting surface cracks in glass using Rayleigh waves and these methods were successfully used in experimental work. Wave propagation in fibre reinforced composites was modelled and experimentally investigated with the results confirming theoretical expectations. Finally a Rayleigh wave was launched onto a fibre reinforced composite sample however the amount of energy leakage into the water was so great, due to the acoustic impedance of water, the detection of the wave was prevented. The conclusion reached was that an immersion setup was not appropriate for launching a travelling Rayleigh wave.</p>

The significance of damage and defects and their detection in composite materials: A review

1992 ◽  
Vol 27 (1) ◽  
pp. 29-42 ◽  
Author(s):  
W J Cantwell ◽  
J Morton
Keyword(s):  
Composite Materials ◽  
Damage Detection ◽  
Failure Modes ◽  
Fracture Mechanisms ◽  
Reinforced Composites ◽  
Load Bearing ◽  
Fibre Composites ◽  
Non Destructive ◽  
Fibre Reinforced Composites ◽  
Non Destructive Techniques

In this paper the various failure modes which occur in long fibre composites are described and discussed. The significance of each of these fracture mechanisms, in terms of their energy-dissipating capacity as well as their effect on the residual load-bearing properties, is considered. A brief review of both the destructive and non-destructive techniques used for detecting and characterizing defects and damage is presented. The ability of each technique to identify the various fracture mechanisms involved in the failure of long fibre reinforced composites is discussed and their overall suitability for damage detection evaluated.

scholarly journals Ultrasonic Non-Destructive  Testing of Fibre Reinforced  Composites

2021 ◽  
Author(s):  
◽  
Matthew Thomson
Keyword(s):  
Experimental Work ◽  
Rayleigh Waves ◽  
Ultrasonic Waves ◽  
Reinforced Composites ◽  
Surface Cracks ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Reinforced Composite ◽  
Non Destructive ◽  
Fibre Reinforced Composites

<p>This thesis focuses on the application of high frequency ultrasound as a tool for performing non-destructive testing for pultruded fibre reinforced composite (FRC) rods. These composite rods are popular in the manufacturing, construction and electrical industries due to their chemical, electrical and strength properties. Such FRCs are manufactured on automated production lines that operate day and night. Non-destructive testing techniques are desired to quickly and accurately detectmanufacturing flaws such as coating thickness irregularities and surface cracks. Layers and cracks can present as large changes in acoustic impedance and will strongly reflect ultrasonic waves. Combined with their low cost, east of use and absense of potentially harmful radiation, ultrasound has proven popular worldwide for Non-Destructive Testing. Finite Element Analysis (FEA) was employed to investigate the propagation of ultrasonic waves through layers of material to simulate a thickness measurement and the ability of ultrasound to measure thicknesses was proven. Experimental work was conducted on two fibre reinforced composite samples with varying thickness coatings of plastic and paint. The thickness was measured accurately using immersion transducers at 50MHz and a resolution of 20μm was attained through the use of matched filtering techniques. Surface acoustic waves, particularly Rayleigh waves were investigated using FEA techniques so that the generation, scattering and detection of such waves was understood. This lead to the development of methods for detecting surface cracks in glass using Rayleigh waves and these methods were successfully used in experimental work. Wave propagation in fibre reinforced composites was modelled and experimentally investigated with the results confirming theoretical expectations. Finally a Rayleigh wave was launched onto a fibre reinforced composite sample however the amount of energy leakage into the water was so great, due to the acoustic impedance of water, the detection of the wave was prevented. The conclusion reached was that an immersion setup was not appropriate for launching a travelling Rayleigh wave.</p>

scholarly journals Detection and Imaging of Damages and Defects in Fibre-Reinforced Composites by Resonance Magnetic Technique

2020 ◽  
Author(s):  
Carine Alves ◽  
Janete Oliveira ◽  
Alberto Tannus ◽  
Alessandra Tarpani ◽  
José Tarpani
Keyword(s):  
Composite Laminates ◽  
Saline Solution ◽  
Pulse Sequences ◽  
Image Interpretation ◽  
Reinforced Composites ◽  
Electrically Conductive ◽  
Distribution Shape ◽  
Non Destructive ◽  
Magnetic Resonance Imaging Equipment ◽  
Fibre Reinforced Composites

Defectively manufactured and deliberately damaged composite laminates fabricated with different continuous reinforcing fibres (respectively, carbon and glass) and polymer matrices (respectively, thermoset and thermoplastic) were inspected in magnetic resonance imaging equipment. Two pulse sequences were evaluated during non-destructive examination conducted in saline solution-immersed samples to simulate load-bearing orthopaedic implants permanently in contact with biofluids. The orientation, positioning, shape, and especially the size of translaminar and delamination fractures were determined according to stringent structural assessment criteria. The spatial distribution, shape, and contours of water-filled voids were sufficiently delineated to infer the amount of absorbed water if thinner image slices than this study were used. The surface texture of composite specimens featuring roughness, waviness, indentation, crushing, and scratches was outlined, with fortuitous artefacts not impairing the image quality and interpretation. Low electromagnetic shielding glass fibres delivered the highest, while electrically conductive carbon fibres produced the poorest quality images, particularly when blended with thermoplastic polymer, though reliable image interpretation was still attainable.

Report and discussion on “The development of fibre reinforced composites for gas turbines”

1969 ◽  
Vol 48 (10) ◽  
pp. 454
Author(s):  
H.E. Gresham ◽  
Eric Mensforth ◽  
L.R. Beesley ◽  
D. Wilkinson ◽  
R.E. Mills ◽  
...  
Keyword(s):  
Gas Turbines ◽  
Reinforced Composites ◽  
Fibre Reinforced Composites

Failure Analysis Strategies for Multistacked Memory Devices with TSV Interconnects

2015 ◽  
Author(s):  
Frank Altmann ◽  
Christian Grosse ◽  
Falk Naumann ◽  
Jens Beyersdorfer ◽  
Tony Veches
Keyword(s):  
Failure Analysis ◽  
Focused Ion Beam ◽  
Failure Modes ◽  
Ion Beam ◽  
Memory Devices ◽  
Metallographic Cross Section ◽  
Electron Beam Induced Current ◽  
Thermal Simulations ◽  
Lock In ◽  
Non Destructive

Abstract In this paper we will demonstrate new approaches for failure analysis of memory devices with multiple stacked dies and TSV interconnects. Therefore, TSV specific failure modes are studied on daisy chain test samples. Two analysis flows for defect localization implementing Electron Beam Induced Current (EBAC) imaging and Lock-in-Thermography (LIT) as well as adapted Focused Ion Beam (FIB) preparation and defect characterization by electron microscopy will be discussed. The most challenging failure mode is an electrical short at the TSV sidewall isolation with sub-micrometer dimensions. It is shown that the leakage path to a certain TSV within the stack can firstly be located by applying LIT to a metallographic cross section and secondly pinpointing by FIB/SEM cross-sectioning. In order to evaluate the potential of non-destructive determination of the lateral defect position, as well as the defect depth from only one LIT measurement, 2D thermal simulations of TSV stacks with artificial leakages are performed calculating the phase shift values per die level.

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