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Abstract: An
equivalent homogenous model is presented for the compact tension (CT)
specimen with different creep properties in the weld and base metals.
Based on the proposed equivalent material model, the modified
experimental C* integral estimation equations are derived for the CT
specimens with a weld centre crack, a fusion line crack and an
asymmetric crack, respectively. And then, finite element (FE) analyses
for C* integral of welded CT specimens are performed by using the ABAQUS
software. The C* parameters from FE simulation and the modified
estimation equations are compared. Results indicated that an
under-mismatched weld will increase the non-dimensional factor hw while
an over-mismatched weld will decrease the hw value compared with the h0
factor of homogeneous CT specimens. It implicates that the current C*
estimation equation in ASTM E1457 may underestimate C* for an
under-mismatched weld but slightly overestimate it for an
over-mismatched weld. Whether for under-mismatched weld (M<1) or for
over-mismatched weld (M>1) considered herein, the predicted C*
parameters from the presented formulae are very close to FE results and
thus can be used to interpret the creep crack growth of weldments
Key words:Material
mismatch Weldseam Creep crack growth CT specimen C* parameter
CLC No: O344.6
TH140.1
上海市自然科学基金(03ZR14022)、国家杰出青年基金(50225517)和上海市启明星计划(05QMX1416)资助项目.Received
20050614,received
in revised form 20051206
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