摘要: |
采用多试样法测试X65和X80两种管材的R曲线、启裂韧性及撕裂模量,对比分析R曲线参量的塑性铰模型法和η因子法。结果表明:塑性铰模型法和基于载荷-裂纹嘴位移曲线的η因子法的测试结果比较接近,基于载荷-加载线位移曲线的η因子法与前两种方法的差别较大;对于中等强度的X65管材,塑性铰模型法、基于载荷-裂纹嘴位移曲线和载荷-加载线位移曲线的η因子法得到的R曲线较为一致,而对高强度的X80管材,这3种方法得到的R曲线偏差较大,特别是δ-R曲线的分散性较高;基于R曲线的撕裂模量趋于稳定,展现了裂纹的稳态扩展特性。 |
关键词: 管道钢 断裂韧性 阻力曲线 多试样法 η因子法 塑性铰模型 |
DOI:10.3969/j.issn.1673-5005.2013.05.024 |
分类号:O 346.1 〖HTH〗 |
基金项目:高等学校博士学科点专项科研基金项目(20100007110006) |
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Study on crack growth resistance curve test of pipeline steel |
SHUAI Jian
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(College of Mechanical and Transportation Engineering in China University of Petroleum, Beijing 102249,China)
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Abstract: |
The R-curve as well as fracture toughness and tearing module were tested for X65and X80steel using multi-specimen method, in which the characteristic parameters were J-integral and CTOD. Plastic hinge model and η factor method were compared. The results show that the test result of plastic hinge model is similar to that of η factor method based on load-crack mouth displacement curves, but has a relative large difference when compared with the test result of η factor method based on load-load line displacement curves. For X65as mid strength pipeline steel, R curves by plastic hinge model and η factor method based on load-crack mouth displacement curves and load-load line displacement curves, are relatively consistent. However, for X80as high strength pipeline steel, R curves, especially δ-R curves by the three methods, have a large dispersion. The tearing modulus based on the R curve tend to be a constant, which represents the steady propagation characteristics of crack. |
Key words: pipeline steel fracture toughness resistance curve multi-specimen method η factor method plastic hinge model |