Three-dimensional crack surface evolution in mode iii delamination toughness tests

J. L. Allison, Ohnston, Michael W. Czabaj, Barry D Davidson, James G. Ratcliffe

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

A study is conducted to determine the manner in which the coupled system of a delamination and multiple transverse cracks evolves and advances in mode III split shear torsion and edge crack torsion delamination toughness tests. Ultrasonic inspection, X-ray computed tomography and microscopy are utilized to view the fracture surface evolution both before and after the onset of planar delamination growth. The three-dimensional fracture surfaces from the two test types are compared to each other and to analogous results from homogeneous and geologic materials. Due to the existence of, and preferential fracture path along, the interlaminar interface in laminated composites, clear differences are found in the behavior of the composites versus that of other materials. Different behaviors in the two types of composite test specimens are also observed and are caused by the proximity of the preimplanted insert to other distinct interfaces: that of the free surfaces in split shear torsion specimens, and of the 90/45 interfaces in edge crack torsion specimens. These interfaces are shown to bound the size of the transverse cracks. This causes differences in the fracture surface evolution between the two composite specimen types and further differentiates the behavior in the composite specimens from that of homogeneous and geologic materials. The application and importance of these observations to mode III delamination toughness testing and delamination growth prediction is described.

Original languageEnglish (US)
Title of host publicationProceedings of the American Society for Composites - 29th Technical Conference, ASC 2014; 16th US-Japan Conference on Composite Materials; ASTM-D30 Meeting
PublisherDEStech Publications
ISBN (Print)9781605951249
StatePublished - 2014
Externally publishedYes
Event29th Annual Technical Conference of the American Society for Composites, ASC 2014; 16th US-Japan Conference on Composite Materials; ASTM-D30 Meeting - La Jolla, San Diego, United States
Duration: Sep 8 2014Sep 10 2014

Other

Other29th Annual Technical Conference of the American Society for Composites, ASC 2014; 16th US-Japan Conference on Composite Materials; ASTM-D30 Meeting
CountryUnited States
CityLa Jolla, San Diego
Period9/8/149/10/14

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ASJC Scopus subject areas

  • Ceramics and Composites

Cite this

Allison, J. L., Ohnston, Czabaj, M. W., Davidson, B. D., & Ratcliffe, J. G. (2014). Three-dimensional crack surface evolution in mode iii delamination toughness tests. In Proceedings of the American Society for Composites - 29th Technical Conference, ASC 2014; 16th US-Japan Conference on Composite Materials; ASTM-D30 Meeting DEStech Publications.