Options
Anisotropic thermal and electrical properties of CFRP
Citation Link: https://doi.org/10.15480/882.17789
Publikationstyp
Doctoral Thesis
Date Issued
2026
Sprache
English
Author(s)
Advisor
Referee
Title Granting Institution
Technische Universität Hamburg
Place of Title Granting Institution
Hamburg
Examination Date
2026-07-30
Institute
TORE-DOI
First published in
Number in series
51
Citation
Technisch-Wissenschaftliche Schriftreihe 51: (2026)
Carbon fiber-reinforced polymers (CFRPs) exhibit strongly anisotropic in-plane thermal and electrical properties, yet efficient identification of laminate-scale transport parameters remains challenging, since the measured response reflects both material architecture and experimental boundary conditions. This thesis establishes non-destructive, model-based methods for single-specimen identification of orthotropic in-plane thermal and electrical transport properties in CFRP laminates and combines them with a non-destructive characterization of laminate lay-up. A pulse-echo ultrasonic workflow evaluates C-scan slices in the Fourier domain and reconstructs the depth-dependent ply-orientation profile. Reliable orientation detection is demonstrated for unidirectional, quasi-isotropic, and Bouligand laminates across varying thicknesses and ply counts. Near-surface regions, porosity, and pronounced geometric features define the methodological boundaries within which the method can be applied and interpreted reliably. Anisotropic thermal transport is quantified by heat-spot infrared thermography combined with an analytical orthotropic diffusion model. Under prescribed heat-flux boundary conditions, the directional response follows the inverse resistivity to diffusion, whose principal-axis values correspond to the longitudinal and transverse thermal diffusivities. This relation enables identification of the directional diffusivities from a single unidirectional specimen through Gaussian-profile broadening and isotherm-evolution analyzes. In addition, a rule-of-mixture approach relates laminate behavior to constituent diffusivities and fiber volume content. Anisotropic electrical transport is characterized using regular n-gonal prismatic specimens, where perimeter-based resistance measurements under full-face electrodes are evaluated by means of effective electrode distance and effective width to identify the principal longitudinal and transverse resistivities. Additional contact- and shunting-dominated configurations clarify the conditions for reliable resistivity measurement.
Subjects
CFRP
Anisotropy
Fiber Orientation
Thermal Conductivity
Electrical Conductivity
DDC Class
620.1: Engineering Mechanics and Materials Science
Publication version
publishedVersion
Loading...
Name
Dissertation_Julian_Karsten_TUHH_Polymer_Composites_Print.pdf
Type
Main Article
Size
40.09 MB
Format
Adobe PDF
Loading...
Name
Dissertation_Julian_Karsten_TUHH_Polymer_Composites_Cover.pdf
Size
6.12 MB
Format
Adobe PDF