Fracture Toughness of Irradiated HT-9 Weld Metal

1985 ◽  
Vol 107 (4) ◽  
pp. 329-333 ◽  
Author(s):  
F. H. Huang ◽  
D. S. Gelles
Keyword(s):  
Fracture Toughness ◽  
Weld Metal ◽  
Fracture Process ◽  
Irradiation Temperature ◽  
Integral Approach ◽  
J Integral ◽  
Test Results ◽  
Weld Material ◽  
Initiation Fracture Toughness ◽  
Scanning Electron

Fracture toughness tests were performed at 93, 205, 316, and 427°C using electropotential techniques on HT-9 weld material irradiated to a fluence of 2.35 × 1022 n/cm2 (E>0.1 MeV) at 390°C. Testing of welds irradiated at 450, 500, and 550°C was performed at 205°C. Test results were analyzed using the J-integral approach. It was found that the initiation fracture toughness of these HT-9 welds increased slightly, while the tearing modulus decreased significantly after irradiation to a fluence of 2.35 × 1022 n/cm2. In addition, results showed that irradiation temperature had little effect on the initiation fracture toughness of HT-9 weld metal. The specimens were examined by scanning electron microscopy after the test in order to understand the fracture process in this weld material.

scholarly journals Study on Crack Propagation of the Tunnel Model under Dynamic Loading

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Chengxiao Li ◽  
Yuantong Zhang ◽  
Peng Xu ◽  
Chen An
Keyword(s):  
Fracture Toughness ◽  
Crack Propagation ◽  
Dynamic Fracture ◽  
Propagation Velocity ◽  
Fracture Process ◽  
Test Results ◽  
Crack Propagation Velocity ◽  
Propagation Law ◽  
Initial Fracture ◽  
The Impact

Crack defects make it difficult to predict the dynamic fracture of tunnel specimens under an impact load. To study the impact of the velocity and crack location on a roadway under dynamic load, specimens with tunnel-type voids were made using polymethyl methacrylate. The split-Hopkinson bar was used as the loading method, and a digital laser dynamic caustics system was used to observe the fracture process of the specimens. The dynamic fracture process was evaluated by the crack propagation velocity, displacement, and dynamic stress intensity factor. To predict and verify the test results, ABAQUS was used to simulate the test process. It was found that the results of the simulated combinations of the crack propagation path and initial fracture toughness change law are consistent with the test results. The initial fracture toughness and the peak value of the crack propagation velocity increased with the increase of the impact velocity. The crack propagation law and trajectory were affected by the location of the prefabricated cracks.

Fracture Properties of Epoxy Asphalt Mixture

2009 ◽  
Vol 417-418 ◽  
pp. 917-920
Author(s):  
Xian Hua Chen ◽  
Hong Tao Li ◽  
Zhen Dong Qian
Keyword(s):  
Fracture Toughness ◽  
Fracture Resistance ◽  
Asphalt Mixture ◽  
J Integral ◽  
Test Results ◽  
High Tensile Strength ◽  
Fracture Properties ◽  
Epoxy Asphalt ◽  
Scb Test ◽  
Good Repeatability

The fracture properties of the thermo-setting materials of epoxy asphalt mixture were evaluated based on J-integral concept and ultimate strength and compared to that of HMA with thermo-plastic binder materials. Totally 60 specimens cored from SGC with different notches were tested with SCB test under a temperature of -10°C and 20°C. The experimental results reveals that epoxy asphalt mixture has a super higher resistance of fracture at low temperature than thermo-plastic HMA due to its super high tensile strength and flexibility, and the influences of temperature on the fracture resistance of EAM is not so significant as that of thermo-plastic HMA. Good repeatability of SCB test results indicates the capability of the SCB test to be useful for measuring the fracture toughness of epoxy asphalt mixture.

scholarly journals Inter-Laboratory Results and Analyses of Mini-C(T) Specimen Testing of an Irradiated Linde 80 Weld Metal

2018 ◽  
Author(s):  
William Server ◽  
Mikhail Sokolov ◽  
Masato Yamamoto ◽  
Robert Carter
Keyword(s):  
Fracture Toughness ◽  
Weld Metal ◽  
Compact Tension ◽  
Laboratory Assessment ◽  
Preliminary Results ◽  
Ductile Crack Growth ◽  
Specimen Test ◽  
Toughness Evaluation ◽  
Initiation Fracture Toughness ◽  
Vessel Material

An irradiated low-upper-shelf Linde 80 weld metal has been tested by four laboratories as part of an inter-laboratory assessment of use of the miniature compact tension [mini-C(T)] test specimen for Master Curve fracture toughness evaluation following ASTM E1921. The preliminary results from each of the laboratories have been compiled and evaluated together to assess the validity and use of the mini-C(T) specimen for an irradiated reactor pressure vessel material which can exhibit ductile crack growth at low temperatures relative to cleavage initiation fracture toughness. The preliminary results from this mini-C(T) testing can also be compared to extensive specimen test results from larger C(T) specimens of the same irradiated material. Comparisons of the results from each of the laboratories and some inter-laboratory differences in the fracture testing are assessed. The evaluations indicate reasonable agreement between the mini-C(T) and larger specimen results, but the selection of test temperature and the number of test specimens needed to obtain reliable results are more difficult when testing a low-upper-shelf toughness material.

Trial Study of the Master Curve Fracture Toughness Evaluation by Mini-C(T) Specimens for Low Upper Shelf Weld Metal Linde-80

2018 ◽  
Author(s):  
Masato Yamamoto
Keyword(s):  
Fracture Toughness ◽  
Weld Metal ◽  
Test Temperature ◽  
Master Curve ◽  
Weld Material ◽  
Ductile Crack Growth ◽  
Toughness Evaluation ◽  
Data Points ◽  
Lower Test ◽  
Mc Method

The Master Curve (MC) method can be used to directly determine fracture toughness of ferritic reactor pressure vessel (RPV) materials. CRIEPI has been working on the development of a testing technique to apply very small C(T) (called Mini-C(T)) specimens for the MC method. The appropriateness of using Mini-C(T) specimens for several materials including un-irradiated plate, forging, weld metal and irradiated plate has been demonstrated. Through a series of investigations, it was determined that more invalid data, due to ductile crack growth (DCG), can occur when using small size specimens. Linde-80 weld metal, used in the fabrication of some RPVs, is known as low upper shelf material, which tends to exhibit more DCG than high upper shelf materials. In the present study, two sets of 15 Mini-C(T) specimens were machined and pre-cracked from irradiated Linde-80 weld metal. Each set of specimens were provided to two different laboratories (A and B). The laboratories separately conducted the MC tests. DCG occurred even in the lower test temperature condition. About half of specimens for lab A showed excessive DCG and were subjected to the censoring. Some of specimens were rejected since the test temperature is outside of the specified range (T-To < −50°C). As a result, lab A could not obtain valid To with 15 specimens. Lab B also experienced DCG, however were able to obtain a sufficient number of valid KJc data points to determine a valid To. The obtained ToQ (lab A) and To (lab B) are sufficiently close to each other and suggests that Mini-C(T) can be used even for the low upper shelf material if the number of available specimens are sufficiently large. The combined dataset from labs A and B estimated To = 31.5°C, which is in the scatter band of To obtained by pre-cracked Chapry (PCCv), 0.5TC(T) or 1TC(T) specimens in a past Heavy-Section Steel Irradiation (HSSI) project. The overall result suggests that To can be estimated using Mini-C(T) specimens for the lower upper shelf weld material, but 15 is a marginal number of specimens for a valid estimation.

Evaluation of impact fracture toughness of polymeric materials by means of the J-integral approach

2003 ◽  
Vol 43 (5) ◽  
pp. 1081-1095 ◽  
Author(s):  
Laura A. Fasce ◽  
Valeria Pettarin ◽  
Roc�o Seltzer ◽  
Patricia M. Frontini
Keyword(s):  
Fracture Toughness ◽  
Polymeric Materials ◽  
Impact Fracture ◽  
Integral Approach ◽  
J Integral

A Simple J-integral Approach for Fracture Toughness Assessment on Invalid Test Data of Standard CT Specimens

2006 ◽  
Vol 1 (2) ◽  
pp. 132-143 ◽  
Author(s):  
V.M.J. Sharma . ◽  
V. Diwakar . ◽  
K. Sree Kumar . ◽  
B. Nageswara Rao . ◽  
S.D. Pathak .
Keyword(s):  
Fracture Toughness ◽  
Test Data ◽  
Integral Approach ◽  
J Integral

Probabilistic Integrity Assessment of Pressure Piping Containing Defects

2010 ◽  
Vol 146-147 ◽  
pp. 390-393
Author(s):  
Ming Li ◽  
Feng Hui Wang ◽  
Ping Wei Chen ◽  
Kang Lou
Keyword(s):  
Experimental Data ◽  
Fracture Toughness ◽  
Weld Metal ◽  
Reliability Assessment ◽  
Assessment Procedure ◽  
J Integral ◽  
Engineering Applications ◽  
Integrity Assessment ◽  
X52 Steel ◽  
Level Analysis

In the present paper, integrity assessment is made to the defects in weld metal zone of pressure piping of X52 steel using the two basic routes, FAD and CDF, which are provided in the European flaw assessment procedure SINTAP. Based on the experimental data various analysis levels of SINTAP are discussed, including the uncommonly used J-integral level in particular. Furthermore, to meet the need of the reliability assessment of pressure piping containing defects in engineering applications, probabilistic procedures are employed to obtain several probability curves with given survivability on the J-integral level with respect to the great scatter of the tested fracture toughness which is required in the J-integral level analysis.

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