Stress intensity factors for long, deep surface flaws in plates under extentional fields

Using a singular solution for a part circular crack by F. W. Smith, a Taylor Series Correction Method (TSCM) was verified for extracting stress intensity factors from photoelastic data. Photoelastic experiments were then conducted on plates with part circular and flat bottomed cracks for flaw depth to thickness ratios of 0.25, 0.50 and 0.75 and for equivalent flaw depth to equivalent ellipse length values ranging from 0.066 to 0.319. Experimental results agreed well with the Smith theory but indicated that the use of the "equivalent" semi-elliptical flaw for correlating the part circular flaw results with semi-elliptical flaw results was not valid for a/2c<< 0.20. Best overall agreement for the moderate (a/t ≃ 0.5) to deep flaws (a/t ≃ 0.75) and a/2c > 0.15 was found with a semi-empirical theory due to J. C. Newman when compared on the basis of equivalent flaw depth and area. The Smith theory, when correlated on the basis of flaw depth and area, appears to yield reasonable estimates (within 10%) of the SIF for flat bottomed flaws for the geometries studied here.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Engineering Science and Mechanics

Department dc:contributor.department

Engineering Science and Mechanics

Grantor dc:publisher

Virginia Polytechnic Institute and State University

Year dc:date.issued

1973

Author dc:creator

• Harms, Alan E.

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en

Handle dc:identifier.uri

http://hdl.handle.net/10919/64694

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/64694