Improvement of Relational Expression between Crack Tip Opening Displacement and Specimen Thickness of Bridge Steel
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摘要: 分析了闫鹏帅等建立的裂纹尖端张开位移（CTOD）与厚度关系式（厚度效应关系式）在应用于桥梁钢时产生较大误差的原因，应用构造法对该关系式进行了改进；使用不同厚度桥梁钢试样（14MnNbq钢、14MnNbq钢接头焊缝、16Mnq钢）的CTOD试验值对改进后的厚度效应关系式进行了验证。结果表明：导致原厚度效应关系式误差较大的原因是平面应力部分的函数形式不合理，以概率密度函数替换该函数后，拟合得到的不同厚度桥梁钢试样的CTOD值与试验值的相对误差较小，改进后的厚度效应关系式适用于不同的桥梁钢。
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关键词:
- 桥梁钢 /
- 裂纹尖端张开位移(CTOD) /
- 厚度效应关系式
Abstract: The reason why the relational expression beteen crack tip opening displacement (CTOD) and thickness (thickness effect expression), which was established by YAN Pengshuai et al., has relatively large errors in the application of bridge steels was analyzed, and then the expression was improved by construction method. The improved thickness effect expression was verified with test values of CTOD of bridge steel specimens (14MnNbq steel, weld of 14MnNbq steel joint, 16Mnq steel) with different thicknesses. The results show that the reason for relatively large errors by the original thickness effect expression was that the function form of the plane stress part was unreasonable. The expression was improved by replacing the unreasonable function with a probability density function. The relative errors between the fitted values by the improved expression and the test values of CTOD of the bridge steel samples with different thicknesses were relatively small. Therefore, the improved thickness effect expression is suitable for different bridge steels. -
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