Specimen size effects in slow strain-rate testing

A study was conducted to evaluate the effect of specimen dimensions in slow strain-rate environmental effects testing. Tension tests of free machining brass were conducted in a mercuric nitrate solution at a constant crosshead displacement rate of 10⁻³(inch/sec). Thirty-six smooth round bar specimens with different dimensions were tested. It was shown that percent elongation to failure was inversely proportional to an effective ratio of length to diameter, ((D - 2a)L / D²), where D is the specimen diameter, L is the length of the reduced cross section of the specimen, and a is the environmentally induced crack depth. This effective length to diameter ratio correlates with the applied tearing modulus for a cracked round bar tension specimen as defined by P. C. Paris and co-workers in 1979. The results verify that the tearing modulus may be used as a parameter to evaluate tearing instability in terms of elastic-plastic fracture mechanics. More directly, these results show a possible source of error in evaluating the degree of susceptibility to environmentally induced cracking in a material-environment interaction.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Materials Engineering

Department dc:contributor.department

Materials Engineering

Grantor dc:publisher

Virginia Polytechnic Institute and State University

Year dc:date.issued

1987

Author dc:creator

• Porr, William C.

Statement dc:rights

• In Copyright

Licence dc:rights.uri

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

Language dc:language.iso

en_US

Handle dc:identifier.uri

http://hdl.handle.net/10919/53153

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/53153