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Fatigue, CTOD and Fracture Toughness Testing

TCR, we have state of the art servo hydraulic universal testing machines of 1000KN, 50 KN and 250 KN capacities for determining fracture toughness parameters like KIC, JIC, δc, KISCC and R-curve for homogeneous metallic materials subjected to quasistatic loading on notched, fatigue pre-cracked specimens. We also conduct Interlaminar Shear Strength (ILSS), Interlaminar Fracture Toughness (GIC), Translaminar Fracture Toughness (KTL) on polymer laminate composites. All our tests are conducted as per ISO, BS, ASTM standards. We also conduct NACE TM0177 DCB Test that measures resistance of metallic materials to environmental assisted cracking, based on fracture mechanics concepts besides NACE TM0284-2003 test for evaluating resistance of pipeline and pressure vessel plate steels to HIC in relatively short time in aqueous sulphide corrosion.  our metallurgists can undertake the CTOD test as per ISO 12737 (formerly BS 7448-1), ISO 15653 (formerly BS 7448-2) and ISO 12135:2002 (Metallic materials -- Unified method of test for the determination of quasistatic fracture toughness) specifications. Tests are carried out at room temperature as well as the same tests can be done in the chilled room using dry ice at the crack tip to maintain a low temperature condition (such as –10 degree centigrade).



TCR Engineering Services (www.tcreng.com), India's leading material testing and metallurgical services company now can undertake Strain-life curve (LCF TEST) on spring materials. Strain-life curve (LCF TEST) on spring material can be conducted if round samples are machined as per relevant ASTM Std. The sample is axially loaded at frequencies in range 5-30 under sine/ramp loading. If the amplitude of the total strain is such that we have significant plasticity, the lifetime is likely to be short (Low Cycle Fatigue or LCF; strain life approach). If the stresses are low enough that the strains are elastic, the lifetime is likely to be long (High Cycle Fatigue or HCF; stress-life approach).


TCR can also undertake the below given tests as per ASTM E8/8M, E21, E 399, E1290, E1820, E813, E466, E606, E647, BS 7448, ISO 12135:


  • Fatigue crack propagation [da/dN vs ΔK Studies]

  • Fracture mechanics [K1c, J1c, CTOD] Testing

  • 3 – point bend testing of materials

  • Spring Fatigue Testing

  • Room temperature and high temperature tests [up to 1000C]

  • Tension/compression

  • Low/High cycle fatigue (LCF/HCF) Testing

  • high temperature tensile tests [up to 1000C]

  • High strain rate testing [300mm/sec on 50KN and 100mm/sec on 250KN UTM]

  • Slow strain rate testing [10-7 mm/sec on 100kN UTM]


Since the last 41 years, TCR Engineering has been constantly updating its material testing, failure analysis, fitness for service consulting and NDT services. We have expanded and now include fatigue, CTOD and fracture toughness testing, stress rupture for both metallic and composite materials.



At the TCR Engineering Services’ materials testing laboratory in Mhape, Navi Mumbai, our metallurgists can undertake the CTOD test as per ISO 15653 (formerly BS 7448-2), ISO 12737 (formerly BS 7448-1) and ISO 12135:2002 (Metallic materials -- Unified method of test for the determination of quasistatic fracture toughness) specifications. Tests are carried out at room temperature as well as the same tests can be done in the chilled room using dry ice at the crack tip to maintain a low temperature condition (such as -10 degree centigrade).


CTOD test can be done as per ISO 12135 or BS 7448-2 on SENB samples fabricated from the pipes up to 40 mm thickness. Single point CTOD shall be calculated at the maximum load. The testing charges is quoted on a per specimen basis plus service tax that includes machining the sample from the pipe, fatigue pre-cracking, testing and evaluation of the result. Client has to provide yield strength, UTS and modulus value for the steel.



TCR has been recently carried out CTOD tests for esteemed clients such as Sorush Energy, NMRL – DRDO (Ambernath), Star Wire (Faridabad) and Al-Can Exports (Talasari).


The Crack Tip Opening Displacement or CTOD Test measures the resistance of a material to the propagation of a crack. CTOD is used on materials that can show some plastic deformation before failure occurs causing the tip to stretch open. Accurate measurement of this displacement is one of the essentials of the test. The CTOD test allows a fitness-for-purpose analysis to be carried out which enables a critical defect size to be calculated. Thus, prior to fabrication, realistic acceptance standards can be set and decisions on appropriate NDE techniques and detection sensitivities can be made. For equipment already in service, it is possible to justify the continued use of cracked or otherwise flawed components until such time as repair or replacement can be affected. Such engineering critical assessments can save a plant operator large amounts of time and money.


Crack Tip Opening Displacement

TCR Engineering Services, India's leading material testing and metallurgical services company routinely undertakes Crack Tip Opening Displacement (CTOD) Test. The Crack Tip Opening Displacement or CTOD Test measures the resistance of a material to the propagation of a crack. CTOD is used on materials that can show some plastic deformation before failure occurs causing the tip to stretch open. Accurate measurement of this displacement is one of the essentials of the test.

Single point CTOD at maximum load can be determined using SENB specimens up to a thickness of 25 mm on 250kN Servo hydraulic UTM of TCR Engineering test lab (www.tcreng.com) at Mumbai. The notch can be placed in target area and tested in chilled condition as per ASTM E1820 which is not different than ISO 15653-2010 which in turn is complementary to ISO 12135. Customers can specify the material and thickness for designing the specimens. Besides, the yield strength, UTS and modulus of the material has to be provided. Minimum 3 samples are required/recommended to be tested. The all-inclusive test charges shall be provided by TCR after knowing the thickness and the product form from which the samples are to be fabricated.

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