Abstract In this paper, the effect of inertia on the steady-state velocity of propagating cracks in modern high toughness pipeline steel was investigated. The steel grades examined in this work were American Petroleum Institute Standard X70 and X100. A tensile plate model, simplified from the geometry of a pipe, was studied using the finite element code ABAQUS 6.14–2. The cohesive zone model (CZM) was used to simulate crack propagation. The CZM parameters were calibrated based on matching the crack tip opening angle (CTOA) measured from a drop-weight tear test (DWTT) finite element model to the experimental CTOA of the material. The CZM parameters were then applied to the tensile plate model. The effect of inertia on the steady-state crack velocity was systematically assessed by altering the density of the material used with the plate model. To isolate the influence of inertia, the effect of strain rate on the fracture process and material hardening was neglected and the CZM parameters were assumed constant. It was found that the steady-state crack velocity decreased with increasing mass density; this is consistent with the effect of backfill in pipeline burst tests. The CTOA extracted from the FE model was not affected by the density.

中文翻译：

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快速韧性断裂：惯性对管钢中传播阻力和 CTOA 的影响

摘要 本文研究了惯性对现代高韧性管线钢裂纹稳态扩展速度的影响。在这项工作中检查的钢种是美国石油协会标准 X70 和 X100。使用有限元代码 ABAQUS 6.14-2 研究了从管道几何结构简化的拉伸板模型。内聚区模型 (CZM) 用于模拟裂纹扩展。CZM 参数是基于匹配从落锤撕裂试验 (DWTT) 有限元模型测量的裂纹尖端张开角 (CTOA) 与材料的实验 CTOA 来校准的。然后将 CZM 参数应用于拉伸板模型。通过改变与板模型一起使用的材料的密度，系统地评估了惯性对稳态裂纹速度的影响。为了隔离惯性的影响，应变率对断裂过程和材料硬化的影响被忽略，CZM 参数被假定为常数。发现稳态裂纹速度随着质量密度的增加而降低；这与回填在管道爆破测试中的效果一致。从有限元模型中提取的 CTOA 不受密度影响。