A Comparative Study on Representativeness and Stochastic Efficacy of Miniature Tensile Specimen Testing
In this article, a miniature dog bone tensile coupon design was tested against the existing ASTM standard specimen design. Specimens were prepared from commercially sourced austenitic stainless steel 304 alloy, and a defect-ridden additively manufactured 304L alloy was studied. By utilizing a tensile specimen design that is 1/230th volume of the smallest ASTM E8-04 (2016), Standard Test Methods for Tension Testing of Metallic Materials, dog bone specimen, coupled to a digital image correlation (DIC) setup, case studies were performed to compare tensile property measurements and strain field evolution. Whereas yield strength measurements were observed to be similar, post-yield, the ultimate strength measurements and ductility measurements from the miniature specimens were observed to be higher than the ASTM specimen design. Although the strength measurements were comparable, the strain evolution was found to differ in the miniature specimens. Studies to assess effects of varying thickness and defect population were also pursued on the miniature tensile specimen. From the DIC strain field estimations, the peak local strain values at ultimate tensile strength were observed to be increasing with reducing specimen thickness. Testing of defect ridden stainless steel revealed the sensitivity to failure through strain localization and the influence of defect size was captured in the strength measurements.
S. Karnati et al., "A Comparative Study on Representativeness and Stochastic Efficacy of Miniature Tensile Specimen Testing," Materials Performance and Characterization, vol. 11, no. 3, ASTM International, Jul 2022.
The definitive version is available at https://doi.org/10.1520/MPC20210136
Mechanical and Aerospace Engineering
Keywords and Phrases
benchmarking study; digital image correlation; high throughput testing; miniature tensile testing; stochastic modeling
International Standard Serial Number (ISSN)
Article - Journal
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11 Jul 2022
U.S. Department of Energy, Grant DE-SC0018879