CFRP Delamination Density Propagation Analysis by Magnetostriction Theory

Author

Brandon Eugene Williams, Clemson UniversityFollow

Date of Award

12-2023

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Mechanical Engineering

Committee Chair/Advisor

Oliver Myers, Ph.D

Committee Member

Garrett Pataky, Ph.D

Committee Member

Gang Li, Ph.D

Committee Member

Zhaoxu Meng, Ph.D

Committee Member

Asha Hall, Ph.D

Abstract

While Carbon Fiber Reinforced Polymers (CFRPs) have exceptional mechanical properties concerning their overall weight, their failure profile in demanding high-stress environments raises reliability concerns in structural applications. Two crucial limiting factors in CFRP reliability are low-strain material degradation and low fracture toughness. Due to CFRP’s low strain degradation characteristics, a wide variety of interlaminar damage can be sustained without any appreciable change to the physical structure itself. This damage suffered by the energy transfer from high- stress levels appears in the form of microporosity, crazes, microcracks, and delamination in the matrix material before any severe laminate damage is observed. This research presents a novel Non- Destructive Evaluation (NDE) technique for assessing subsurface interlaminar interphacial health. A new self-sensing smart composite material is born by embedding microscopic magnetically activated sensors between CFRP ply. Magnetostrictive Carbon Fiber Reinforced Polymer (MagCFRP) is a self-sensing structural health composite material that is magnetically activated by an external magnetic field. This research merges the governing magnetoelasticity and general magnetization mechanics with analytical, experimental, and numerical results. For mode I and mode II fiber- matrix debonding, cracking, and shear delamination, there was an observed localized magnetic flux density gradient of more than 3 mT (2%) with a reversible flux of only 25% for low driving magnetic flux density (≈ 0.2 T) using the indirect magnetization stimulation method.

Recommended Citation

Williams, Brandon Eugene, "CFRP Delamination Density Propagation Analysis by Magnetostriction Theory" (2023). All Dissertations. 3487.
https://open.clemson.edu/all_dissertations/3487