An Experimental Measurement of Toughness Locus for a Ductile Material

Abstract:

A toughness locus Jc-Q for a ductile steel, SA106 Grade C used in the main steam piping of nuclear power plants, has been experimentally evaluated. Along with the standard fracture test procedure for J-R curve, Q as the second parameter governing stress triaxiality nearby the crack tip is measured from the displacements nearby the side necking which occurs near the crack tip on the lateral surface of a fracture specimen. The displacements nearby the side necking are measured from the digital images taken during the fracture experiment based on Stereoscopic Digital Photography (SDP) and high resolution Digital Image Correlation (DIC) software. The crack length is monitored by Direct Current Potential Drop (DCPD) method and the J-R curve is determined according to ASTM standard E1737-96. The effects of crack length, specimen geometry and thickness of specimen are studied, which are included in the toughness locus Jc-Q.

• Periodical: Key Engineering Materials (Volumes 297-300)
• Pages: 2410-2415
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.297-300.2410
• Online since: November 2005
• Authors: Dong Hak Kim, Jeong Hyun Lee, Ho Dong Kim, Ki Ju Kang
• Keywords: Digital Image Correlation (DIC), Q-Parameter, Side Necking, Stereoscopic Digital Photography, Toughness Locus

References

[1] D.H. Kim, J.H. Lee and K.J. Kang: Transaction of the KSME Vol. 29 (2003), pp.1607-1613.

[2] D.H. Kim and K.J. Kang: Applicability of Experimental Method to Evaluate Stress Triaxiality near the Crack Tip, in preparation (2004).

[3] ASTM E1737-96: Standard Test Method for J-Integral Characterization of Fracture Toughness, Annual Book of ASTM Standards Vol. 03. 01. (1998).

[4] Y.Y. Earmme and Y.B. Lee: Study of Effect of Dynamic Strain Aging on Fracture Toughness for Main Stream Line Piping of Nuclear Power Plant, Korea Electric Power Corporation (1996).

[5] K.J. Kang, S.Y. Kim, H.J. Kim and D.Y. Jeung: Nuclear Engineering and Design Vol. 219 (2003), pp.11-18.

[6] D.H. Kim, J.H. Lee and K.J. Kang: The Application of the Experimental Method of Measuring Q to Ductile Material, in preparation (2004).