{ "id": "epyf7eyj3e", "slug": "fracture-testing", "title": "Fracture testing", "updated": "2026-10-25", "topic_path": [ { "id": "technology", "label": "Technology and the built world", "api_url": "https://www.edgepedia.org/api/v1/topics/technology" }, { "id": "technology.engineering", "label": "Engineering and manufacturing", "api_url": "https://www.edgepedia.org/api/v1/topics/technology.engineering" }, { "id": "technology.engineering.engineering.materials.metallurgy", "label": "Materials science and metallurgy", "api_url": "https://www.edgepedia.org/api/v1/topics/technology.engineering.engineering.materials.metallurgy" } ], "geo": [ { "id": "geo.nongeo.t1800.technology.engineering.engineering.materials.metallurgy", "label": "Non-geographic · 1800 to 1945: Materials science and metallurgy", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.nongeo.t1800.technology.engineering.engineering.materials.metallurgy", "path": [ { "id": "geo.nongeo", "label": "Non-geographic", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.nongeo" }, { "id": "geo.nongeo.t1800", "label": "Non-geographic · 1800 to 1945", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.nongeo.t1800" }, { "id": "geo.nongeo.t1800.technology", "label": "Technology and the built world", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.nongeo.t1800.technology" }, { "id": "geo.nongeo.t1800.technology.engineering", "label": "Engineering and manufacturing", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.nongeo.t1800.technology.engineering" }, { "id": "geo.nongeo.t1800.technology.engineering.engineering.materials.metallurgy", "label": "Materials science and metallurgy", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.nongeo.t1800.technology.engineering.engineering.materials.metallurgy" } ] }, { "id": "geo.nongeo.t1946.technology.engineering.engineering.materials.metallurgy", "label": "Non-geographic · 1946 to 2000: Materials science and metallurgy", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.nongeo.t1946.technology.engineering.engineering.materials.metallurgy", "path": [ { "id": "geo.nongeo", "label": "Non-geographic", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.nongeo" }, { "id": "geo.nongeo.t1946", "label": "Non-geographic · 1946 to 2000", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.nongeo.t1946" }, { "id": "geo.nongeo.t1946.technology", "label": "Technology and the built world", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.nongeo.t1946.technology" }, { "id": "geo.nongeo.t1946.technology.engineering", "label": "Engineering and manufacturing", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.nongeo.t1946.technology.engineering" }, { "id": "geo.nongeo.t1946.technology.engineering.engineering.materials.metallurgy", "label": "Materials science and metallurgy", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.nongeo.t1946.technology.engineering.engineering.materials.metallurgy" } ] } ], "excerpt": "Fracture testing is a family of mechanical test methods that measure a cracked metal specimen's resistance to crack extension, yielding toughness values like K, J, and CTOD.", "snippet": "Fracture testing is a family of mechanical test methods that measure a cracked metal specimen's resistance to crack extension, yielding toughness values like K, J, and CTOD.", "node": "technology.engineering.engineering.materials.metallurgy", "markdown": "# Fracture testing\n\nFracture testing is a family of mechanical test methods that load metal specimens containing a sharp, fatigue-produced crack and measure the material's resistance to crack extension. The quantities produced are the plane-strain fracture toughness \\( K_{\\mathrm{Ic}} \\), the elastic-plastic parameters J and CTOD (\\( \\delta \\)), and resistance curves (R-curves) of toughness versus crack extension.[1](https://store.astm.org/e1820-25a.html) [Fracture toughness](https://www.edgepedia.org/fracture-toughness) data feed damage-tolerant assessments of pipelines and welds, and standard test results can otherwise be overly conservative for real shallow cracks.[2](https://www.sciencedirect.com/science/article/abs/pii/S030801611630045X) • [3](https://webstore.ansi.org/preview-pages/BSI/preview_30366165.pdf)\n\n| Key fact | Detail |\n|---|---|\n| Quantities measured | K, J, and CTOD (\\( \\delta \\)), as point values or R-curves, in Mode I loading[1](https://store.astm.org/e1820-25a.html) |\n| \\( K_{\\mathrm{Ic}} \\) conditions | Predominantly linear-elastic, plane-strain; fatigue-precracked specimens at least 1.6 mm thick; based on crack growth up to 2% of specimen width[4](https://store.astm.org/e0399-24.html) |\n| Size validity | Thickness B, crack length a, and the ligament W−a must exceed \\( 2.5(K_{\\mathrm{Ic}}/\\sigma_{\\mathrm{YS}})^{2} \\); the test is invalid if \\( P_{\\max}/P_{Q} > 1.10 \\)[5](https://fenix.tecnico.ulisboa.pt/downloadFile/1970943312370126/E399_Kic.pdf) |\n| Elastic-plastic standards | ASTM E1820-23a and ISO 12135 are the most widely used ductile-regime test standards[6](https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=935316) |\n| SENT testing | BS 8571 determines CTOD and J on single-edge-notched tension specimens, developed primarily for pipeline girth welds[3](https://webstore.ansi.org/preview-pages/BSI/preview_30366165.pdf) |\n| Precrack quality | Sharp electric-discharge-machined notches overestimate toughness by more than 20% relative to fatigue precracks in low-toughness AM Ti-6Al-4V[7](https://pmc.ncbi.nlm.nih.gov/articles/PMC7890697/) |\n\n## How it works\n\nA pre-existing sharp crack concentrates the elastic stress field at its tip. The stress-intensity factor K is proportional to the square root of the force tending to cause crack extension, and the energy release rate G is the energy exchanged per unit crack extension, regarded as the force tending to extend the crack.[8](https://www.bu.edu/moss/files/2020/08/Irwin1956-StressesStrainsNearEndofaCrack.pdf) For a linear-elastic material the HRR crack-tip field reduces to the elastic field, with \\( J = G = K^{2}/E' \\), where \\( E' = E \\) in [plane stress](https://www.edgepedia.org/plane-stress) and \\( E' = E/(1-\\nu^{2}) \\) in plane strain (stress state in thick material where deformation in one direction is suppressed).[29](https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1096&context=usnavyresearch) • [9](https://www.gruppofrattura.it/ocs/index.php/esis/CP2009/paper/viewFile/9339/6174)\n\nWhen the material yields extensively at the crack tip, linear elasticity no longer applies. The energy-balance approach traces to an early-1920s analysis balancing strain-energy relaxation against surface energy, extended to metals in the late 1940s by including plastic dissipation in the total energy release; the [J-integral](https://www.edgepedia.org/j-integral) then characterizes elastic-plastic crack-tip fields.[10](https://link.springer.com/article/10.1557/s43577-022-00379-2) CTOD, the crack-tip opening displacement, serves as an engineering fracture parameter for the same regime.[1](https://store.astm.org/e1820-25a.html) Constraint matters: a high-constraint, deep-cracked bend specimen yields a lower R-curve, while a low-constraint specimen produces a higher R-curve.[2](https://www.sciencedirect.com/science/article/abs/pii/S030801611630045X)\n\n## How it is done\n\nThe practitioner selects a geometry, machines a notch, sharpens it with a fatigue crack, loads the specimen, and records load versus displacement while tracking crack growth. E399 recommends SE(B), C(T), DC(T), A(T), and A(B) specimens; E1820 uses SE(B), C(T), and DC(T).[4](https://store.astm.org/e0399-24.html) • [1](https://store.astm.org/e1820-25a.html) The nominal crack length is 0.50W; a straight-across starter notch root radius must not exceed 0.08 mm, or 0.25 mm for a chevron notch.[5](https://fenix.tecnico.ulisboa.pt/downloadFile/1970943312370126/E399_Kic.pdf) In a \\( K_{\\mathrm{Ic}} \\) test, the load \\( P_{Q} \\) is found by the 5% secant method, a secant slope of 95% of the initial elastic slope, intended to define toughness at 2% or less crack extension.[11](https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1048&context=usnavyresearch)\n\nCrack extension during a single-specimen test is measured several ways. In the elastic unloading compliance technique, the specimen is partially unloaded at intervals; as the crack grows the specimen becomes less stiff and the compliance increases, giving instantaneous crack length.[12](https://jzus.zju.edu.cn/opentxt.php?doi=10.1631%2Fjzus.A0930004) Alternatives are direct-current electric potential drop and the normalization technique, which needs only load-displacement data plus crack sizes measured before and after the test, simplifying testing in extreme conditions.[12](https://jzus.zju.edu.cn/opentxt.php?doi=10.1631%2Fjzus.A0930004) • [13](https://www.prci.org/Research/DesignMaterialsConstruction/DMCProjects/API-2-1/3151/158294.aspx) • [14](https://info.ornl.gov/sites/publications/Files/Pub119732.pdf) [Digital image correlation](https://www.edgepedia.org/digital-image-correlation) tracks the crack by monitoring crack opening displacement between the crack lips and drives a finite-element sub-model with the measured displacement field.[15](https://www.mdpi.com/2673-3161/7/1/3) ISO 12135:2021 Annex H details single-specimen CTOD and J R-curve methods using partial unloading compliance and electrical resistance.[16](https://webstore.ansi.org/preview-pages/bsi/preview_30394398.pdf)\n\n## Origin\n\nASTM Committee E24 on Fracture Testing of Metals was established in 1958 to develop fracture-property test methods; E09 and E24 merged in 1993 as the present Committee E08. The E399 draft was proposed in 1966, issued tentatively as E399-70T in ASTM STP 463, and balloted as E399-72, becoming the model for subsequent fracture test standards.[11](https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1048&context=usnavyresearch) The first J-based standard, ASTM E813, appeared in 1981 and accepted only the critical J at the onset of ductile tearing; E1152-87 added J-R curves and split J into elastic and plastic parts, \\( J = J_{\\mathrm{el}} + J_{\\mathrm{pl}} \\).[12](https://jzus.zju.edu.cn/opentxt.php?doi=10.1631%2Fjzus.A0930004) • [2](https://www.sciencedirect.com/science/article/abs/pii/S030801611630045X) E813 and E1152 were withdrawn in 1997, replaced by E1737, which was discontinued in 1998 when the first E1820 edition appeared; ISO 12135's precursors were the ESIS P1 and P2 procedures of January 1992.[6](https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=935316) ISO 12135:2021 supersedes BS 7448-1:1991 and BS 7448-4:1997, unifying single-point and resistance-curve testing.[16](https://webstore.ansi.org/preview-pages/bsi/preview_30394398.pdf) Recent E1820 editions removed \\( K_{\\mathrm{Ic}} \\) evaluation and refer users to E399, so that all applicable parameters come from a single test.[1](https://store.astm.org/e1820-25a.html)\n\nThe SENT methods central to pipeline assessment trace to a constraint-corrected SENT approach for pipeline fracture assessment introduced by Matteo Chiesa and colleagues in Engineering Fracture Mechanics in 2001,[17](https://doi.org/10.1016/s0013-7944%2800%2900129-6) to unloading-compliance crack-size evaluation for SENT by G. Shen and W. R. Tyson in the Journal of Testing and [Evaluation](https://www.edgepedia.org/evaluation) in 2009,[18](https://doi.org/10.1520/jte102368) and to CTOD resistance curves in side-grooved SENT specimens from full-field deformation measurements by M.A. Verstraete and colleagues in Engineering Fracture Mechanics in 2013.[19](https://doi.org/10.1016/j.engfracmech.2013.07.015)\n\n## Variants\n\nThe compact tension C(T), single-edge bend SE(B), and disk-shaped compact DC(T) geometries serve general \\( K_{\\mathrm{Ic}} \\), J, and CTOD testing.[4](https://store.astm.org/e0399-24.html) For pipelines, the SENT (single-edge-notched tension) specimen reproduces the tensile, low-constraint loading of girth-weld flaws. BS 8571 gives CTOD and J methods on SENT specimens, including R-curves and single-point values at unstable extension or pop-in.[3](https://webstore.ansi.org/preview-pages/BSI/preview_30366165.pdf) The CANMET SE(T) design uses a square cross-section (\\( B \\times B \\), \\( B = W \\)) with side grooves and a 10W grip-to-grip length, tested by single-specimen unloading compliance with the J approach of E1820; the DNV-RP-F108 SE(T) method instead requires a minimum of six valid multiple-specimen tests.[20](https://www.sciencedirect.com/science/article/abs/pii/S0308016117300388)\n\n## Applications\n\nFracture toughness data support structural-integrity assessment across industries. SENT testing is the pipeline industry's method for girth welds experiencing plastic straining during installation; low-constraint tests represent the realistic loading of girth-weld defects and can remove unnecessary conservatism from assessments.[3](https://webstore.ansi.org/preview-pages/BSI/preview_30366165.pdf) • [21](https://journal.hep.com.cn/fme/EN/10.1007/s11465-018-0501-2) The Damage Tolerant Design Handbook compiles \\( K_{\\mathrm{Ic}} \\), R-curve, fatigue crack growth, and \\( K_{\\mathrm{ISCC}} \\) data for stainless steels, titanium, nickel-base, alloy steels, and 2000-, 6000-, and 7000-series aluminum alloys.[22](https://apps.dtic.mil/sti/tr/pdf/ADA141901.pdf) In nuclear surveillance, the miniature compact tension specimen MC(T) allows four specimens per broken half-Charpy, and ten MC(T) samples occupy roughly the irradiation volume of one full-size Charpy specimen.[23](https://www.osti.gov/etdeweb/servlets/purl/20902506) Additively manufactured parts are a growing application: HIP-treated AM Ti-6Al-4V measured \\( J_{Q} \\) of 110–150 kJ/m² (\\( K_{Q} \\) 119–139 \\( \\mathrm{MPa}\\sqrt{\\mathrm{m}} \\)) on fatigue-precracked Charpy-type specimens, with lack-of-fusion pores giving the lowest value.[7](https://pmc.ncbi.nlm.nih.gov/articles/PMC7890697/)\n\n## Limitations and alternatives\n\nA \\( K_{\\mathrm{Ic}} \\) result is valid only if both thickness B and crack length a exceed \\( 2.5(K_{\\mathrm{Ic}}/\\sigma_{\\mathrm{YS}})^{2} \\), with \\( \\sigma_{\\mathrm{YS}} \\) the 0.2% offset yield strength at the test temperature and loading rate; required specimen size grows as the square of the toughness-to-yield-strength ratio, and a failed test generally requires a specimen at least 1.5 times larger. Fatigue precracking limits apply: terminal-stage \\( K_{\\max} \\) must not exceed 60% of \\( K_{\\mathrm{Ic}} \\), with \\( K_{\\max}/E \\le 0.002 \\, \\mathrm{in}^{1/2} \\) and stress ratio between −1 and +0.1.[5](https://fenix.tecnico.ulisboa.pt/downloadFile/1970943312370126/E399_Kic.pdf) If \\( P_{\\max}/P_{Q} \\) exceeds 1.10, \\( K_{Q} \\) may bear no relation to \\( K_{\\mathrm{Ic}} \\).[5](https://fenix.tecnico.ulisboa.pt/downloadFile/1970943312370126/E399_Kic.pdf) Residual stresses bias \\( K_{Q} \\) and \\( K_{\\mathrm{Ic}} \\), especially in specimens from as-heat-treated stock, weldments, and additively manufactured products.[4](https://store.astm.org/e0399-24.html)\n\nIn SENT testing, a survey of over 400 specimens showed most fatigue precrack front curvatures exceeded the older 10% limit, but finite-element analysis showed up to 17% curvature causes errors in J and CTOD not exceeding 10% and 7%, so a 20% of \\( a_{0} \\) curvature limit was recommended.[24](https://www.twi-global.com/technical-knowledge/published-papers/development-of-a-british-standard-single-edge-notch-tension-sent-test-method-bs8571) The three E399 load-displacement curve types (small-scale yielding, pop-in, and failure before 5% nonlinearity) give different \\( P_{Q} \\) values for the same material, causing scatter even in conforming tests.[25](https://asmedigitalcollection.asme.org/appliedmechanics/article/93/11/111003/1234785/The-Size-Dependence-of-Plane-Strain-Fracture)\n\nWhether \\( K_{\\mathrm{Ic}} \\) is a size-insensitive lower bound is disputed. E399 states it represents a lower limiting value for 2% apparent crack extension at the test temperature and speed,[4](https://store.astm.org/e0399-24.html) but peer-reviewed analysis concludes this classical interpretation is incorrect for both brittle and ductile fractures, since \\( K_{\\mathrm{Ic}} \\) varies with crack and ligament size even when the E399 criteria are met, and data should be scaled to actual structure size for transferability.[25](https://asmedigitalcollection.asme.org/appliedmechanics/article/93/11/111003/1234785/The-Size-Dependence-of-Plane-Strain-Fracture) Proposals to determine \\( K_{Q} \\) at a fixed crack growth of 0.5 mm, or 2% of the ligament, aim to eliminate this size effect.[11](https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1048&context=usnavyresearch) E399-24 accordingly adds an optional \\( K_{\\mathrm{Isi}} \\) procedure based on a fixed 0.5 mm crack extension, less sensitive to specimen size than \\( K_{\\mathrm{Ic}} \\),[4](https://store.astm.org/e0399-24.html) and ISO 12135:2021 lowered the initial testing-rate limit from 0.5 to 0.3 \\( \\mathrm{MPa} \\cdot \\mathrm{m}^{0.5} \\cdot \\mathrm{s}^{-1} \\) and revised CTOD formulae to include the yield-to-tensile strength ratio, since the old BS 7448 formulae overestimate CTOD for high strain-hardening materials.[16](https://webstore.ansi.org/preview-pages/bsi/preview_30394398.pdf)\n\nUpper-shelf Charpy energy \\( C_{v} \\) correlates with critical J (\\( J_{Q} \\)) only empirically: \\( C_{v} \\) includes post-peak propagation and shear-lip energy, while \\( J_{Q} \\) concerns the onset of stable ductile tunnelling; using pre-peak instrumented energy \\( C_{vm} \\) removes most of the elongation effect on the correlation.[26](https://link.springer.com/article/10.1007/s10704-025-00901-y) The tests also differ physically: Charpy strain rates reach about \\( 10^{4} \\, \\mathrm{s}^{-1} \\) versus about \\( 10^{-2} \\, \\mathrm{s}^{-1} \\) in quasi-static SENB tests, and the notch-tip versus crack-tip stress states differ (triaxiality about 1.7 in Charpy versus about 2.2 in SENB).[27](https://repository.tudelft.nl/file/File_357bf5a7-16f5-4d46-a8ed-915715d3c6e1) Minimum Charpy values such as 100 J serve as indirect toughness requirements but have been shown inadequate in certain situations involving cracks.[26](https://link.springer.com/article/10.1007/s10704-025-00901-y) Small specimens trade accuracy for material economy: MC(T) specimens systematically underestimate initiation toughness relative to standard 1T C(T) specimens (overall \\( J_{Q}|J_{\\mathrm{Ic}} \\) ratio 0.69 ± 0.170), with J-R curves deviating above roughly 200 kJ/m² in J.[23](https://www.osti.gov/etdeweb/servlets/purl/20902506) ASTM E1921 Master Curve testing is restricted to high-constraint SE(B) and C(T) specimens with a/W between 0.45 and 0.55; low-constraint SE(T) practice is not codified for cleavage characterization.[28](https://cris.vtt.fi/ws/portalfiles/portal/105810253/1-s2.0-S0013794424005976-main.pdf) [Tensile testing](https://www.edgepedia.org/tensile-testing) supplies the yield strength used in validity checks rather than a toughness measure itself.[5](https://fenix.tecnico.ulisboa.pt/downloadFile/1970943312370126/E399_Kic.pdf)\n\n## References\n\n1. [ASTM E1820-25A Standard Test Method for Measurement of Fracture Toughness](https://store.astm.org/e1820-25a.html)\n2. [Review of fracture toughness test methods for ductile materials in low-constraint conditions (Zhu, Int J Pressure Vessels and Piping 2016)](https://www.sciencedirect.com/science/article/abs/pii/S030801611630045X)\n3. [BS 8571:2018 Method of test for determination of fracture toughness in metallic materials using single edge notched tension (SENT) specimens](https://webstore.ansi.org/preview-pages/BSI/preview_30366165.pdf)\n4. [ASTM E399-24 Standard Test Method for Linear-Elastic Plane-Strain Fracture Toughness of Metallic Materials](https://store.astm.org/e0399-24.html)\n5. [ASTM E399 (older edition) full text, Plane-Strain Fracture Toughness of Metallic Materials](https://fenix.tecnico.ulisboa.pt/downloadFile/1970943312370126/E399_Kic.pdf)\n6. [NIST paper on J-integral DCG corrections comparing ASTM E1820 and ISO 12135 procedures](https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=935316)\n7. [Effect of Precrack Configuration and Lack-of-Fusion on the Elastic-Plastic Fracture Toughness of Additively Manufactured Ti-6Al-4V Parts (NIST)](https://pmc.ncbi.nlm.nih.gov/articles/PMC7890697/)\n8. [Analysis of Stresses and Strains Near the End of a Crack Traversing a Plate (Irwin, 1956/1957)](https://www.bu.edu/moss/files/2020/08/Irwin1956-StressesStrainsNearEndofaCrack.pdf)\n9. [A Brief History of the Crack Tip Stress Intensity Factor and Fracture Mechanics (Anderson, ESIS 2009)](https://www.gruppofrattura.it/ocs/index.php/esis/CP2009/paper/viewFile/9339/6174)\n10. [100 years after Griffith: From brittle bulk fracture to failure in 2D materials (MRS Bulletin, 2022)](https://link.springer.com/article/10.1557/s43577-022-00379-2)\n11. [Review of Fracture Toughness (G, K, J, CTOD, CTOA) Testing and Standardization (Zhu & Joyce, Engineering Fracture Mechanics 2012)](https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1048&context=usnavyresearch)\n12. [Zhu, 'J-integral resistance curve testing and evaluation', J Zhejiang Univ Sci A 2009;10(11):1541-1560](https://jzus.zju.edu.cn/opentxt.php?doi=10.1631%2Fjzus.A0930004)\n13. [PRCI PR-214-114509-R01 Standardization of Weld Testing for Fracture Toughness using Single Edge Notched Tests](https://www.prci.org/Research/DesignMaterialsConstruction/DMCProjects/API-2-1/3151/158294.aspx)\n14. [Technical Manual for Automated J-R Curve Analysis Program Based on the ASTM E1820-18 Normalization Method (ORNL)](https://info.ornl.gov/sites/publications/Files/Pub119732.pdf)\n15. [Fracture-Toughness-Based Methodology for Determination of 3D-Printed Specimen Using Digital Image Correlation](https://www.mdpi.com/2673-3161/7/1/3)\n16. [BS ISO 12135:2021 National foreword (BSI), Metallic materials: Unified method of test for determination of quasistatic fracture toughness](https://webstore.ansi.org/preview-pages/bsi/preview_30394398.pdf)\n17. [Efficient fracture assessment of pipelines. A constraint-corrected SENT specimen approach (Engineering Fracture Mechanics, 2001)](https://doi.org/10.1016/s0013-7944%2800%2900129-6)\n18. [G. Shen, W. R. Tyson (2009). Crack Size Evaluation Using Unloading Compliance in Single-Specimen Single-Edge-Notched Tension Fracture Toughness Testing. Journal of Testing and Evaluation.](https://doi.org/10.1520/jte102368)\n19. [M.A. Verstraete and colleagues (2013). Determination of CTOD resistance curves in side-grooved Single-Edge Notched Tensile specimens using full field deformation measurements. Engineering Fracture Mechanics.](https://doi.org/10.1016/j.engfracmech.2013.07.015)\n20. [CANMET SENT test method, updates and applications](https://www.sciencedirect.com/science/article/abs/pii/S0308016117300388)\n21. [Recent development in low-constraint fracture toughness testing for structural integrity assessment of pipelines](https://journal.hep.com.cn/fme/EN/10.1007/s11465-018-0501-2)\n22. [Damage Tolerant Design Handbook: A Compilation of Fracture and Crack-Growth Data for High-Strength Alloys](https://apps.dtic.mil/sti/tr/pdf/ADA141901.pdf)\n23. [Use of Miniaturized Compact Tension Specimens for Fracture Toughness Measurements in the Upper Shelf Regime (SCK•CEN, OSTI)](https://www.osti.gov/etdeweb/servlets/purl/20902506)\n24. [Development of a British Standard Single Edge Notch Tension (SENT) Test Method (BS8571), TWI](https://www.twi-global.com/technical-knowledge/published-papers/development-of-a-british-standard-single-edge-notch-tension-sent-test-method-bs8571)\n25. [The Size-Dependence of Plane Strain Fracture Toughness: A Mechanistic Analysis (ASME Journal of Applied Mechanics)](https://asmedigitalcollection.asme.org/appliedmechanics/article/93/11/111003/1234785/The-Size-Dependence-of-Plane-Strain-Fracture)\n26. [Damage-mechanics insights into the relationship between upper-shelf Charpy testing and J-integral testing (International Journal of Fracture, 2025)](https://link.springer.com/article/10.1007/s10704-025-00901-y)\n27. [Damage mechanics model for correlating notch toughness in Charpy impact tests with fracture toughness in cracked static fracture tests (TU Delft)](https://repository.tudelft.nl/file/File_357bf5a7-16f5-4d46-a8ed-915715d3c6e1)\n28. [Low constraint fracture toughness testing for master curve reference temperature determination using 10 mm-thick SE(B) and SE(T) specimens (Engineering Fracture Mechanics, 2024)](https://cris.vtt.fi/ws/portalfiles/portal/105810253/1-s2.0-S0013794424005976-main.pdf)\n29. [Viewcontent.cgi (digitalcommons.unl.edu)](https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1096&context=usnavyresearch)\n\n---\n*Topic: Encyclopedia › Technology and the built world › Engineering and manufacturing › Materials science and metallurgy*\n\n*Initially written Sep 29, 2026 · Reviewed: Sep 30, 2026 · Edited: Sep 30, 2026; Oct 25, 2026 · Last review: Sep 30, 2026*\n\n*Copyright 2026 EdgeChat AI, a subsidiary of Biostate AI.*\n\nLicense: Edgepedia Community License 1.0, https://www.edgepedia.org/edgepedia/license\n", "same_as": [], "url": "https://www.edgepedia.org/fracture-testing", "markdown_url": "https://www.edgepedia.org/fracture-testing.md", "license": { "name": "Edgepedia Community License 1.0", "url": "https://www.edgepedia.org/edgepedia/license", "summary": "Free with credit, commercial use included. AI training is open to everyone. For other uses, organizations over USD 100M in revenue or 100M monthly users license separately.", "spdx": "LicenseRef-Edgepedia-Community-1.0" }, "credit": "\"Fracture testing\", Edgepedia (EdgeChat), https://www.edgepedia.org/fracture-testing. Edgepedia Community License 1.0.", "credit_md": "\"[Fracture testing](https://www.edgepedia.org/fracture-testing)\", Edgepedia (EdgeChat), [https://www.edgepedia.org/fracture-testing](https://www.edgepedia.org/fracture-testing). [Edgepedia Community License 1.0](https://www.edgepedia.org/edgepedia/license).", "credit_html": "\"Fracture testing\", Edgepedia (EdgeChat), https://www.edgepedia.org/fracture-testing. Edgepedia Community License 1.0.", "speakable": "Fracture testing is a family of mechanical test methods that measure a cracked metal specimen's resistance to crack extension, yielding toughness values like K, J, and CTOD." }