Local Yielding Around a Crack Tip in Plexiglas

[+] Author and Article Information
P. S. Theocaris

The National Technical University, Athens, Greece

J. Appl. Mech 37(2), 409-415 (Jun 01, 1970) (7 pages) doi:10.1115/1.3408521 History: Received April 25, 1969; Revised November 10, 1969; Online April 06, 2010


An optical method was developed to study the highly strained region surrounding small edge cracks in brittle transparent materials loaded in tension. Interference of the partially reflected coherent monochromatic light beam from the front and back surfaces of the specimen prepared from an optically isotropic and inert material, gave a fringe pattern which depicted the thickness variation of the plate in the neighborhood of the crack. The fringe pattern consisted of a dense pattern surrounding the crack tip which was separated from the rest by a distinct bright envelope. It was shown for the material studied that the limiting envelope was a circle which, when projected to a screen, became an epicycloid. The evolution of the geometric characteristics of the highly strained zone with increasing load was studied, up to the critical load for a rapid crack propagation. The data obtained yielded an insight on the mechanism of fracture in brittle materials.

Copyright © 1970 by ASME
Your Session has timed out. Please sign back in to continue.






Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In