【摘要】 现有国际上被广泛应用的标准中临界压缩应变计算公式主要基于弯曲试验结果建立，未充分考虑轴压等其他载荷形式对管道屈曲行为的影响，为探明《油气输送管道线路工程抗震技术规范》(GB/T 50470—2017)在计算轴压载荷和弯曲载荷作用下管道临界压缩应变的适用性问题，通过数值模拟的方法开展分析研究。采用非线性有限元软件建立数值仿真模型比较两种载荷条件下管道的屈曲响应特点，分析不同参数对屈曲的影响，并将不同条件下的临界压缩应变与《油气输送管道线路工程抗震技术规范》(GB/T 50470—2017)中推荐公式计算得到的结果进行对比。结果表明：随着内压的增加，轴压模型临界压缩应变有随之增加的趋势，而弯曲模型临界压缩应变趋势为先降低后增加；随着径厚比与屈强比的增加，轴压模型与弯曲模型临界压缩应变都有随之减小的趋势。《油气输送管道线路工程抗震技术规范》(GB/T 50470—2017)的结果相较于弯曲模型是保守的，但对轴压模型结果是不保守的，可见在管道基于应变设计中以往忽略载荷特征的做法存在不合理性。基于模拟结果，将轴压载荷的实际影响纳入管道屈曲失效的评估体系，回归得到一种精确度更高，同时考虑了一定保守性的计算管道临界压缩应变的解析公式，研究成果为管道工程的安全设计和运行提供了重要的理论依据和技术支持。更多还原

【Abstract】 The critical compressive strain calculation formulas widely adopted in international standards are primarily established based on bending test results, with insufficient consideration of the effects of other load forms such as axial compression on pipeline buckling behavior. To investigate the applicability of Code for Seismic Design of Oil and Gas Transmission Pipeline Engineering(GB/T 50470—2017) in calculating critical compressive strains under axial compression and bending loads, an analytical study was conducted through numerical simulations. Nonlinear finite element software was employed to establish numerical models, through which the buckling response characteristics of pipelines under the two load conditions were compared. The influences of different parameters on buckling were analyzed, and critical compressive strains under various conditions were contrasted with results calculated using the formula recommended in Code for Seismic Design of Oil and Gas Transmission Pipeline Engineering(GB/T 50470—2017). The results indicate that as internal pressure increases, the critical compressive strain of the axial compression model exhibits an upward trend, whereas that of the bending model first decreases and then increases. With the rise of diameter-to-thickness ratio and yield-to-tensile strength ratio, critical compressive strains of both axial compression and bending models decreases. While the Code for Seismic Design of Oil and Gas Transmission Pipeline Engineering(GB/T 50470—2017) results are conservative compared to the bending model, they are non-conservative for the axial compression model, revealing the unreliability of neglecting load characteristics in strain-based pipeline design. Based on simulation results, the practical influence of axial compression loads was incorporated into the assessment framework for pipeline buckling failure. A refined analytical formula with higher accuracy and appropriate conservatism was derived through regression analysis for calculating critical compressive strains. The findings provide essential theoretical foundations and technical support for the safe design and operation of pipeline engineering.更多还原