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Experimental Mechanics

, Volume 45, Issue 2, pp 144–152 | Cite as

Experimental determination of cohesive failure properties of a photodegradable copolymer

  • J. Abanto-Bueno
  • J. Lambros
Article

Abstract

In this paper we present a methodology to measure the material traction-separation relation for a poly(ethylene carbon monoxide) copolymer, ECO. This material exhibits a ductile-to-brittle transition when subjected to ultraviolet irradiation and undergoes a change of failure mechanism, from shear yielding to crazing, in the process. Single edge notched tension specimens of ECO irradiated for 50 h were used to generate slow-speed stable crack growth, predominantly from material crazing. Full-field measurements of the in-plane deformation around the growing crack tip were performed using the optical technique of digital image correlation. A multicamera setup was used in which simultaneous measurement of both the far-field displacement and that directly surrounding the craze was performed. The far-field results were used to obtain a value of the energy release rate supplied to the crack tip region. The near-tip results were used to extract a material traction-separation law in the regime of steady-state crack growth. A softening traction-separation relation was measured. The area under the traction-separation curve was then compared with the simultaneous far-field measurements and the agreement was very good (within 6.5%) validating the experimental methodology used.

Key Words

Cohesive properties fracture polyethylene digital image correlation multiscale testing 

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Copyright information

© Society for Experimental Mechanics 2005

Authors and Affiliations

  • J. Abanto-Bueno
    • 1
  • J. Lambros
    • 2
  1. 1.Department of Mechanical EngineeringBradley UniversityPeopriaUSA
  2. 2.Department of Aerospace EngineeringUniversity of Illinois at Urbana-ChampaignUrbanaUSA

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