Use of portable/in situ stress-strain microprobe system to measure stress-strain behavior and damage in metallic materials and structures
- Advanced Technology Corp., Oak Ridge, TN (United States)
- Oak Ridge National Lab., TN (United States)
- North Carolina State Univ., Raleigh, NC (United States)
A novel portable/in situ Stress-Strain Microprobe (SSM) system was used to measure true-stress/true-plastic-strain ({sigma}{sub t}-{epsilon}{sub p}) behavior of several metallic materials, welds, and their heat-affected-zones (HAZs) in various metallurgical and damage conditions. The SSM system utilized an automated ball indentation (ABI) technique to measure elastic modulus, yield strength, {sigma}{sub t}-{epsilon}{sub p} curve, strength coefficient, strain-hardening-exponent (uniform ductility), and to estimate fracture toughness (from the ABI-measured flow properties) in carbon steels, stainless steels, nickel alloys, aluminum alloys, titanium alloys, zirconium alloys, etc. Numerous ABI tests were also conducted on several nuclear pressure vessel steels (NPVSs) in the unirradiated, neutron irradiated, and post-irradiated thermally-annealed conditions. For all these test materials and conditions, the ABI-derived results were in good agreement with those from conventional standard test methods. Furthermore, the nondestructive ABI test results rigorously indicated the various levels of neutron-embrittlement damage and the percentage of ductility recovery following thermal annealing of the NPVS specimens. In situ/nondestructive structural applications of the SSM system and its ABI technique have been demonstrated by testing a circumferentially welded stainless steel pipe and a full-thickness section of a nuclear pressure vessel (using 90{degrees}V-blocks and magnetic mounts for temporary attachment of the SSM testing head to the pipe and the steel section, respectively). All SSM localized tests were computer-controlled and conducted in less than 2 minutes per ABI test; depending on the desired strain rate. Example test results on metallic structural components and samples are presented in this paper. 21 refs., 5 figs., 1 tab.
- OSTI ID:
- 577631
- Report Number(s):
- CONF-960580-; TRN: 98:000998-0005
- Resource Relation:
- Conference: ASTM symposium on nontraditional methods of sensing stress, strain, and damage in materials and structures, Orlando, FL (United States), 20 May 1996; Other Information: PBD: 1997; Related Information: Is Part Of Nontraditional methods of sensing stress, strain, and damage in materials and structures; Lucas, G.F.; Stubbs, D.A. [eds.]; PB: 241 p.
- Country of Publication:
- United States
- Language:
- English
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