4 research outputs found
Multi-layer carbon fiber reinforced plastic characterization and reconstruction using eddy current pulsed thermography
Ph. D. Thesis.Carbon fibre composite materials are widely used in high-value, high-profit
applications, such as aerospace manufacturing and shipbuilding – due to their low
density, high mechanical strength, and flexibility. Existing NDT techniques such as
eddy current testing suffers from electrical anisotropy in CFRP (carbon fibre reinforced
plastics). Ultrasonic is limited by substantial attenuation of signal caused by the multilayer structure. The eddy current pulsed thermography has previously been applied for
composites NDE (non-destructive evaluation)such as impact damage, which has the
ability for quick and accurate QNDE(quantitative non-destructive evaluation)
inspection but can be challenging for detection and evaluation of sub-surface defects,
e.g., delamination and debonding in multiple layer structures. Developing QNDE
solutions using eddy current thermography for addressing subsurface defects evaluation
in multi-layer and anisotropic CFRP is urgently required.
This thesis proposes the application of eddy current pulsed thermography (ECPT) and
ECPuCT (eddy current pulse compression thermography) for tackling the challenges of
anisotropic properties and the multi-layer structure of CFRP using feature-based and
reconstruction-based QNDE and material characterisation. The major merit for eddy
current heating CFRP is the volumetric heating nature enabling subsurface defect
detectability. Therefore, the thesis proposes the investigation of different ECPT and
their features for QNDE of various defects, including delamination and debonding.
Based on the proposed systems and QNDE approach, three case studies are
implemented for delamination QNDE, debonding QNDE, conductivity estimation and
orientation inverse reconstruction using the two different ECPT systems and features,
e.g., a pulse compression approach to increase the capability of the current ECPT
system, the feature-based QNDE approach for defect detection and quantification,
and reconstruction-based approach for conductivity estimation and inversion. The
three case studies include 1) investigation of delamination with different depths in terms
of delamination location, and depth quantification using K-PCA, proposed temporal
feature-crossing point feature and ECPuCT system; 2) investigation of debonding with
different electrical and thermal properties in terms of non-uniform heating pattern
removal and properties QNDE using PLS approaches, impulse response based feature
Numerical Simulations
This book will interest researchers, scientists, engineers and graduate students in many disciplines, who make use of mathematical modeling and computer simulation. Although it represents only a small sample of the research activity on numerical simulations, the book will certainly serve as a valuable tool for researchers interested in getting involved in this multidisciplinary field. It will be useful to encourage further experimental and theoretical researches in the above mentioned areas of numerical simulation
Bowdoin Orient v.103, no.1-23 (1973-1974)
https://digitalcommons.bowdoin.edu/bowdoinorient-1970s/1004/thumbnail.jp