TY - GEN
T1 - Measurement of fracture toughness of materials with non-uniform microstructure based on spiral notch torsion test
AU - Zhang, Wei
AU - Feng, Zhili
AU - Wang, Jy An
PY - 2010
Y1 - 2010
N2 - Materials such as welds consist of highly non-uniform distribution of microstructure. It is typically difficult to measure fracture toughness of those materials using the conventional testing approaches such as ASTM compact tension test, since the non-uniform microstructure can induce irregular crack propagation front. In this study, the spiral notch torsion test(SNTT)is enhanced to measure the fracture toughness of welds. Thetestspecimen resembles a round tensile bar with a spiral-shaped notch on the circumference. To introduce non-uniform microstructure, the heat treatment with a Gleeble system is used to rapidly heat and quench the specimen. the heating and cooling rates applied are typical of those experienced in welding. the hardness distribution inthe axial directionof as-heat-treated specimen has a bell shape centered in the middle of the specimen. This distribution resembles that in a transverse section of a weldment. During loading, the specimen is twisted about its axis. It is possible to achieve a Mode I crack front that is long enough to meet the plain strain state and other fracture mechanics requirements for testing the local toughness of weld region. Fracture toughness calculation based on finite element analysis is performed to convert the recordedload-displacementinto the fracture toughness KIc.
AB - Materials such as welds consist of highly non-uniform distribution of microstructure. It is typically difficult to measure fracture toughness of those materials using the conventional testing approaches such as ASTM compact tension test, since the non-uniform microstructure can induce irregular crack propagation front. In this study, the spiral notch torsion test(SNTT)is enhanced to measure the fracture toughness of welds. Thetestspecimen resembles a round tensile bar with a spiral-shaped notch on the circumference. To introduce non-uniform microstructure, the heat treatment with a Gleeble system is used to rapidly heat and quench the specimen. the heating and cooling rates applied are typical of those experienced in welding. the hardness distribution inthe axial directionof as-heat-treated specimen has a bell shape centered in the middle of the specimen. This distribution resembles that in a transverse section of a weldment. During loading, the specimen is twisted about its axis. It is possible to achieve a Mode I crack front that is long enough to meet the plain strain state and other fracture mechanics requirements for testing the local toughness of weld region. Fracture toughness calculation based on finite element analysis is performed to convert the recordedload-displacementinto the fracture toughness KIc.
UR - http://www.scopus.com/inward/record.url?scp=80155147712&partnerID=8YFLogxK
U2 - 10.1115/PVP2010-26112
DO - 10.1115/PVP2010-26112
M3 - Conference contribution
AN - SCOPUS:80155147712
SN - 9780791849255
T3 - American Society of Mechanical Engineers, Pressure Vessels and Piping Division (Publication) PVP
SP - 223
EP - 228
BT - American Society of Mechanical Engineers, Pressure Vessels and Piping Division (Publication) PVP
T2 - ASME 2010 Pressure Vessels and Piping Division/K-PVP Conference, PVP2010
Y2 - 18 July 2010 through 22 July 2010
ER -