IAEA Coordinated Research Project on Master Curve Approach to Monitor Fracture Toughness of RPV Steels: Effect of Loading Rate

2007 ◽  
Author(s):  
Hans-Werner Viehrig ◽  
Enrico Lucon
Keyword(s):  
Fracture Toughness ◽  
Master Curve ◽  
Loading Rate ◽  
Crack Arrest ◽  
Dynamic Fracture Toughness ◽  
Current Status ◽  
Research Project ◽  
Topic Area ◽  
Loading Rates ◽  
Data Assessment

In the final evaluation for the application of the Master Curve in the IAEA Coordinated Research Project Phase 5 (CRP-5), one of the areas which was identified as needing further work concerned the effects of loading rate on the reference temperature To up to impact loading conditions. This subject represents one of the three topic areas within the current CRP-8. The effect of loading rate can be broken down into two distinct aspects: 1) the effect of loading rate on the Master Curve To values for loading rates within the specified in ASTM E1921-05 for quasi-static loading (0.1–2 MPa√m/s); 2) the effect of loading rate on To values for higher loading rates, including impact conditions using instrumented precracked Charpy (PCC) specimens. The new CRP includes both aspects, but primarily focuses on the second element of loading rate effects, i.e. loading rates above 2 MPa√m/s. These issues are investigated within the topic area #2 of CRP-8 (Loading Rate Effect). The mandatory portion of this topic area required participation in a round-robin exercise (RRE) to validate the application of the Master Curve approach to PCC specimens tested in the ductile-to-brittle transition region using an instrumented pendulum (10 tests per participant on the JRQ material). The current status of the RRE is presented in [1]. The non-mandatory portion of this topic area consists in providing Master Curve data obtained at different loading rates on various RPV steels, in order to assess the loading rate dependence of To and compare it with an empirical model proposed by Wallin. Moreover, additional topics will be addressed, such as: • comparison of results from unloading compliance and monotonic loading in the quasi-static range; • estimation of fracture toughness from Charpy V-notch data; • assessment of crack arrest properties from instrumented Charpy results; • effect of irradiation on the relationship between static and dynamic fracture toughness.

Fracture Mechanics at Elevated Loading Rates in the Ductile to Brittle Transition Region

2017 ◽  
Author(s):  
Uwe Mayer ◽  
Thomas Reichert ◽  
Johannes Tlatlik
Keyword(s):  
Fracture Toughness ◽  
Dynamic Loading ◽  
Dynamic Fracture ◽  
Master Curve ◽  
Crack Arrest ◽  
Dynamic Fracture Toughness ◽  
Fracture Probability ◽  
High Rate ◽  
Loading Rates ◽  
Static Conditions

The rate-dependent reference temperature T0,x characterizes the fracture toughness of ferritic steels at the onset of cleavage. Fracture toughness values KJc,d were determined according to the Annex A1 of ASTM E1921 [1] which refers to the high rate annexes A14 and A17 of ASTM E1820 [2]. Results of extensive dynamic fracture toughness experiments at various loading rates, temperatures, specimen types and sizes revealed shortcomings in the transferability of the shape of the Master Curve under quasi-static conditions to elevated loading rates. In particular, the quasi-static Master Curve predicts lower fracture toughness values towards higher temperatures than experimentally observed under dynamic loading causing a steeper Master Curve shape. Fractographic examinations proved the relevance of local crack arrest under dynamic loading conditions, which is consistent with the view of the parallelism of dynamic fracture probability and probability of arrest.

scholarly journals Fracture Toughness of Fresh-Water Ice

1979 ◽  
Vol 22 (86) ◽  
pp. 135-143 ◽  
Author(s):  
H. W. Liu ◽  
K. J. Miller
Keyword(s):  
Fracture Toughness ◽  
Melting Point ◽  
Fresh Water ◽  
Loading Rate ◽  
Crack Arrest ◽  
Plane Strain Fracture Toughness ◽  
Water Ice ◽  
Loading Rates ◽  
Strain Fracture ◽  
Static Fracture

AbstractThe plane-strain fracture toughness of fresh-water ice was measured at various loading rates and temperatures. The fracture toughness of ice decreases as loading rate increases and as the test temperature approaches the melting point. The presence of liquid water seems to reduce the fracture toughness. The fracture toughness for crack arrest is slightly lower than the static fracture toughness.

IAEA Coordinated Research Project on Master Curve Approach to Monitor Fracture Toughness of RPV Steels: Final Results of the Experimental Exercise to Support Constraint Effects

2009 ◽  
Author(s):  
Randy K. Nanstad ◽  
Milan Brumovsky ◽  
Rogelio Herna´ndez Callejas ◽  
Ferenc Gillemot ◽  
Mikhail Korshunov ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Master Curve ◽  
Reference Temperature ◽  
Compact Specimen ◽  
Bias Effect ◽  
Research Project ◽  
Topic Area ◽  
Energy Agency ◽  
Experimental Part

The precracked Charpy single-edge notched bend, SE(B), specimen (PCC) is the most likely specimen type to be used for determination of the reference temperature, T0, with reactor pressure vessel (RPV) surveillance specimens. Unfortunately, for many RPV steels, significant differences have been observed between the T0 temperature for the PCC specimen and that obtained from the 25-mm thick compact specimen [1TC(T)], generally considered the standard reference specimen for T0. This difference in T0 has often been designated a specimen bias effect, and the primary focus for explaining this effect is loss of constraint in the PCC specimen. The International Atomic Energy Agency (IAEA) has developed a coordinated research project (CRP) to evaluate various issues associated with the fracture toughness Master Curve for application to light-water RPVs. Topic Area 1 of the CRP is focused on the issue of test specimen geometry effects, with emphasis on determination of T0 with the PCC specimen and the bias effect. Topic Area 1 has an experimental part and an analytical part. Participating organizations for the experimental part of the CRP performed fracture toughness testing of various steels, including the reference steel JRQ (A533-B-1) often used for IAEA studies, with various types of specimens under various conditions. Additionally, many of the participants took part in a round robin exercise on finite element modeling of the PCVN specimen, discussed in a separate paper. Results from fracture toughness tests are compared with regard to effects of specimen size and type on the reference temperature T0. It is apparent from the results presented that the bias observed between the PCC specimen and larger specimens for Plate JRQ is not nearly as large as that obtained for Plate 13B (−11°C vs −37°C) and for some of the results in the literature (bias values as much as −45°C). This observation is consistent with observations in the literature that show significant variations in the bias that are dependent on the specific materials being tested. There are various methods for constraint adjustments and two methods were used that reduced the bias for Plate 13B from −37°C to −13°C in one case and to − 11°C in the second case. Unfortunately, there is not a consensus methodology available that accounts for the differences observed with different materials. Increasing the Mlim value in the ASTM E-1921 to ensure no loss of constraint for the PCC specimen is not a practicable solution because the PCC specimen is derived from CVN specimens in RPV surveillance capsules and larger specimens are normally not available. Resolution of these differences are needed for application of the master curve procedure to operating RPVs, but the research needed for such resolution is beyond the scope of this CRP.

scholarly journals Fracture Toughness of Fresh-Water Ice

1979 ◽  
Vol 22 (86) ◽  
pp. 135-143 ◽  
Author(s):  
H. W. Liu ◽  
K. J. Miller
Keyword(s):  
Fracture Toughness ◽  
Melting Point ◽  
Fresh Water ◽  
Loading Rate ◽  
Crack Arrest ◽  
Plane Strain Fracture Toughness ◽  
Water Ice ◽  
Loading Rates ◽  
Strain Fracture ◽  
Static Fracture

AbstractThe plane-strain fracture toughness of fresh-water ice was measured at various loading rates and temperatures. The fracture toughness of ice decreases as loading rate increases and as the test temperature approaches the melting point. The presence of liquid water seems to reduce the fracture toughness. The fracture toughness for crack arrest is slightly lower than the static fracture toughness.

Effect of Loading Rate on Fracture Toughness of Pressure Vessel Steels

2000 ◽  
Vol 122 (2) ◽  
pp. 125-129 ◽  
Author(s):  
K. K. Yoon ◽  
W. A. Van Der Sluys ◽  
K. Hour
Keyword(s):  
Fracture Toughness ◽  
Pressure Vessel ◽  
Master Curve ◽  
Loading Rate ◽  
Dynamic Fracture Toughness ◽  
Reference Temperature ◽  
Ferritic Steels ◽  
Transition Range ◽  
High Loading Rate ◽  
Pressure Vessel Steels

The master curve method has recently been developed to determine fracture toughness in the brittle-to-ductile transition range. This method was successfully applied to numerous fracture toughness data sets of pressure vessel steels. Joyce (Joyce, J. A., 1997, “On the Utilization of High Rate Charpy Test Results and the Master Curve to Obtain Accurate Lower Bound Toughness Predictions in the Ductile-to-Brittle Transition, Small Specimen Test Techniques,” Small Specimens Test Technique, ASTM STP 1329, W. R. Corwin, S. T. Rosinski, and E. Van Walle, eds., ASTM, West Conshohocken, PA) applied this method to high loading rate fracture toughness data for SA-515 steel and showed the applicability of this approach to dynamic fracture toughness data. In order to investigate the shift in fracture toughness from static to dynamic data, B&W Owners Group tested five weld materials typically used in reactor vessel fabrication in both static and dynamic loading. The results were analyzed using ASTM Standard E 1921 (ASTM, 1998, Standard E 1921-97, “Standard Test Method for the Determination of Reference Temperature, T0, for Ferritic Steels in the Transition Range,” 1998 Annual Book of ASTM Standards, 03.01, American Society for Testing and Materials, West Conshohocken, PA). This paper presents the data and the resulting reference temperature shifts in the master curves from static to high loading rate fracture toughness data. This shift in the toughness curve with the loading rate selected in this test program and from the literature is compared with the shift between KIc and KIa curves in ASME Boiler and Pressure Vessel Code. In addition, data from the B&W Owners Group test of IAEA JRQ material and dynamic fracture toughness data from the Pressure Vessel Research Council (PVRC) database (Van Der Sluys, W. A., Yoon, K. K., Killian, D. E., and Hall, J. B., 1998, “Fracture Toughness of Ferritic Steels and ASTM Reference Temperature T0,” BAW-2318, Framatome Technologies. Lynchburg, VA) are also presented. It is concluded that the master curve shift due to loading rate can be addressed with the shift between the current ASME Code KIc and KIa curves. [S0094-9930(00)01302-0]

Determination of Dynamic Fracture Toughness at High Loading Rates

2012 ◽  
Author(s):  
Uwe Mayer
Keyword(s):  
Fracture Toughness ◽  
Elastic Waves ◽  
Crack Arrest ◽  
Dynamic Fracture Toughness ◽  
High Loading ◽  
Dynamic Crack ◽  
Testing Time ◽  
Loading Rates ◽  
Propagation Of Elastic Waves

To determine fracture mechanics values at high loading rates from force and displacement signals requires the influences of inertia and the propagation of elastic waves to be taken into account. This paper shows how measurement technique requirements can be fulfilled for determination of key values for a testing time below 100μs for 1T C(T) specimens. Results using this method are given for specimens of 22 NiMoCr 3 7 steel (A 508 C1.2) from a project on correlation between dynamic crack initiation and crack arrest.

Investigation of loading rate and plate thickness effects in dynamic fracture toughness of PMMA

1997 ◽  
Vol 57 (4) ◽  
pp. 459-460
Author(s):  
H. Wada ◽  
M. Seika ◽  
T.C. Kennedy ◽  
C.A. Calder ◽  
K. Murase
Keyword(s):  
Fracture Toughness ◽  
Dynamic Fracture ◽  
Loading Rate ◽  
Plate Thickness ◽  
Dynamic Fracture Toughness
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