Flame-sprayed Al-12Si Coatings as Damage Detection Sensors for Fibre-Reinforced Polymer Composites

• Author / Creator

  Gonzalez Henriquez, Raelvim

• In this thesis, a characterization of flame sprayed aluminium 12silicon (Al 12Si) coatings as an electrical structural health monitoring (SHM) sensor for fibre reinforced polymer composite (FRPC) structures is presented. Flame sprayed Al 12Si coatings were deposited onto FRPC tubes and laminates. The effect of the flame sprayed Al 12Si coating on the failure behaviour of FRPC tubulars was evaluated by internal pressurization tests with hydraulic oil, and mitigation of the mechanical degradation effects due to the flame spray deposition on the performance of FRPC tubes was achieved. The application of the classical laminate model to describe the mechanical behaviour of flame spray coated FRPC laminates under uniaxial loads was evaluated considering the flame sprayed Al 12Si coating as an isotropic lamina. An electrical SHM sensor for uniaxial FRPC structures was developed based on the changes of electrical behavior of the porous Al 12Si coatings under applied load. Tensile tests were performed on cross-ply and unidirectional coated FRPC laminates to evaluate the electromechanical response of the flame sprayed SHM sensor (FS SHM sensor). The development of a descriptive framework for damage detection in FRPC laminates based on electrical resistance change was accomplished in tandem with the analysis of the cost structure of the proposed FS SHM sensor at the current development stage. The characterization of flame sprayed Al 12Si coatings as electrical SHM sensors provided a macroscopic description of the electro-mechanical behaviour of the novel metal FRPC structure and established the limitations to structural damage detection induced by strain. Further technical improvements in the sensitivity of the FS SHM sensor to detect matrix damage at low strain level may be realized by considering the effect of microstructural porosity and morphology on the electrical properties of the Al 12Si coating. The economic analysis of the proposed FS SHM sensor revealed the relatively high cost-effectiveness of this approach to damage detection in FRPC structures and assessed the initial and operational cost factors required for potential technology development and competitive implementation of the proposed FS SHM sensor in uniaxial FRPC structures.

• Subjects / Keywords

  • Damage Detection
  • Composites
  • Thermal spraying

• Graduation date

  Fall 2015

• Type of Item

  Thesis

• Degree

  Doctor of Philosophy

• DOI

  https://doi.org/10.7939/R3N29PJ3R

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.