Creep crack growth modelling of Grade 91 vessel weldments using a modified ductility based damage model
Creep crack growth modelling of Grade 91 vessel weldments using a modified ductility based damage model
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DOI：
10.1016/j.euromechsol.2021.104424
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发表时间：
2022-01
期刊：
影响因子：
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通讯作者：
Raheeg Ragab;J. Parker;Ming Li;Tao Liu;Wei Sun
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文献类型：
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作者：
Raheeg Ragab;J. Parker;Ming Li;Tao Liu;Wei Sun
在Kachanov-Rabotnov连续介质损伤力学(CDM)模型的基础上，利用延性耗尽的概念，建立了91级容器焊件高温蠕变裂纹扩展模型。与现有模型相比，提出的模型具有一个关键优势，因为它需要识别和校准的材料常数更少。将改进后的模型应用于ABAQUS中的用户自定义子程序中，对91级容器焊接件的蠕变裂纹扩展进行了预测。预测的蠕变裂纹萌生和扩展发生在与封头有关的焊接件的热影响区，与相应的容器试验结果吻合较好。此外，用该模型预测的缺口棒材和容器的蠕变断裂寿命与实验结果吻合较好。这表明改进的基于延性的损伤模型可用于高温结构的蠕变裂纹扩展和寿命预测。
This paper reports creep crack growth modelling of Grade 91 vessel weldments at high temperature using a modified ductility-based continuum damage mechanics (CDM) model, which is based on the Kachanov-Rabotnov CDM and utilizing the concept of ductility exhaustion. The proposed model holds a key advantage over existing models in that it requires fewer material constants to be identified and calibrated. The new modified model was implemented into a user-defined subroutine in ABAQUS and then used to predict the creep crack growth of Grade 91 vessel weldments. Creep crack initiation and growth in the vessels were predicted to occur in the heat-affected zones of the weldments associated with the end closures, which is in good agreement with the corresponding vessel tests. Further, the predicted creep rupture lives of the notched bars and the vessels using the proposed model correlated reasonably well against the experimental results. This suggests that the modified ductility-based damage model can be used for creep crack growth and life prediction for high temperature structures with confidence.