PSI - Issue 68

Mr. Parthasarathy Iyengar et al. / Procedia Structural Integrity 68 (2025) 446–452 P. Iyengar, J. Mardaras, S. Soe / Structural Integrity Procedia 00 (2025) 000–000

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to be tempered based upon the material. It is believed to be more applicable to special alloys such as Ti-6Al-4v. A relevant method when presented with limitation in thickness for extraction of K 1C specimen, ASTM E 740 by ASTM (2023) provides a rigorous standard based upon Newman and Raju (1979). Although a relationship may be applied between K 1C and K 1 e the effort required to test is comparable. It is believed to be suitable for ‘thin’ parts. 5.2. Testing of notched cylindrical specimen with lathe turned notches The concept of specimen is pending further effort to qualify the approach such as by use of round-robin testing involving a variety of suppliers with agreeable statistical sample for an industry-representative diversity of alloys, it is believed that controlled semi-ductile notch geometry may be proposed in future. Indicative values from semi-ductile NRBs may be developed to assess material quality in serial production and is not seen as a substitute during characterization. Acknowledgements The authors are grateful to Mr. Robert Haldane and Arconic Manufacturing (GB) LTD, Kitts Green, UK for providing us with K 1C test results from bespoke 2024-T351 plate for further processing by Airbus. 6. References ASTM, ASTM E 399-23, 2023. Standard Test Method for Linear-Elastic Plane-Strain Fracture Toughness of Metallic Materials, pp 1-40 ASTM, ASTM E 740/740M-23, 2023. Standard Practice for Fracture Testing with Surface-Crack Tension Specimens MMPDS, MMPDS- 14, 2019. [Washington, D.C.]: Federal Aviation Administration; [Columbus, Ohio]: Battelle Memorial Institute Dharne, B.V. et al., 2015. Effect of Specimen Diameter and notch angle on the Fracture Toughness of Al7075 T6 Alloy-An Experimental Approach, International Journal of Research in Engineering and Technology, pp 1-5 Hahn, G.T., Rosenfield, A.R., 1965. Local Yielding and Extension of a Crack under Plane Stress, Acta Metallurgica, Vol. 13, pp. 293-306 Janssen, M., Zuidema, J., Wanhill, R. J. H., 2024. “Fracture Mechanics An Engineering Primer”, VSSD Second edition 2002-2006, TU Delft OPEN Publishing, ISBN: 978-94-6366-818-7, Chapter 3 Raju, I.S., Newman, J.C. Jr., 1979. Stress Intensity Factors for a Wide Range of Semi-Elliptical Surface Cracks in Finite Thickness Plates, Engineering Fracture Mechanics, Vol. 11, pp. 817-829 Ramberg, W., Osgood, W. R., 1943. Description of stress–strain curves by three parameters. Technical Note No. 902, National Advisory Committee for Aeronautics, Washington DC. Sarchamy, D., M.G. Burns, A. Nadkarni, 1996. Investigation into the use of miniature specimens for the determination of K1C and K1SCC values, European Conference on Fracture 11th Edition, France, pp 1-7 Wang.C.H., 1996. Introduction to Fracture Mechanics; Stress analysis of cracked bodies. Aeronautical and Maritime Research Laboratory, Victoria 3001, Melbourne, DSTO-GD-0103 Wells, D.N., James, M.A., Allen, P.A., Wallin, K.R.W., 2018. “A Review of the Proposed K1si Offset-Secant Method for Size Insensitive Linear Elastic Fracture Toughness Evaluation,” Materials Performance and Characterization, Vol. 7, No. 2, pp. 1-14 Wilson, C. D., 1997. Fracture Toughness Testing with Notched Round Bars, Doctoral dissertation, University of Tennessee – Knoxville, USA