The Essential Work of Fracture Method Applied to Mode II Interlaminar Fracture in Fiber Reinforced Polymers

• Author / Creator

  McKinney, Scott D

• This thesis presents a new method for determining mode II interlaminar fracture toughness in fiber reinforced polymers (FRP) using the essential work of fracture (EWF) method. Fracture tests were performed on a tabbed double edge notched shear (DENS) specimen, made from a unidirectional glass/epoxy laminate, in an Iosipescu fixture. The EWF in mode II was found to agree with the GIIc for fracture initiation value from an ENF test.
  A finite element model was used to determine mechanisms involved in the DENS specimen. Interlaminar fracture was simulated using cohesive elements and the unstable crack growth path was simulated using the Riks arc length method. The numerical results closely match the empirical results. The model reveals that even though the EWF could be found using the conventional linear extrapolation, elastic strain energy, rather than the usual plastic energy, is the dominant geometry dependent property.

• Subjects / Keywords

  • Finite elements
  • Composite Materials
  • Essential Work of Fracture
  • Cohesive Zone
  • Interlaminar Fracture Toughness
  • Fiber Reinforced Polymers
  • Iosipescu
  • Mode II Fracture

• Graduation date

  Spring 2013

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/R3JM82

• 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.