基于韧性损伤模型的管道凹坑缺陷应变评估
发布时间：2018-11-16 20:55
【摘要】：为提高管道凹坑缺陷应变评估方法的准确性,基于韧性断裂模型和损伤力学,建立管道凹坑损伤评估模型。结合有限元方法,研究2种典型凹坑缺陷(平滑型凹坑和曲折型凹坑)不同区域的损伤程度,计算在不同管规格和内压下的凹坑缺陷临界失效应变。数值模拟结果表明:不同类型凹坑的各部位损伤程度不同,且可能产生裂纹的部位也不同;不同管规格之间的临界失效应变差别较小;由于内压的回弹作用,不同内压下的非约束型凹坑的临界失效应变不同,可进而得到内压和临界失效应变的拟合关系;凹坑缺陷的应变评估需要将凹坑分为约束型和非约束型,选用不同的应变标准分别予以评估。
[Abstract]:In order to improve the accuracy of the method for evaluating the defect and strain of the pipe pit, the damage assessment model of the pipe is established based on the ductile fracture model and damage mechanics. Combined with finite element method, the damage degree in different regions of two typical concave defects (smooth and zigzag pits) is studied, and the critical failure strain of concave defects under different pipe specifications and internal pressure is calculated. The results of numerical simulation show that the damage degree of different types of pits is different and the positions where cracks may occur are different, and the critical failure strain difference between different pipe specifications is relatively small. Due to the springback of internal pressure, the critical failure strain of unconstrained pit under different internal pressure is different, and the fitting relationship between internal pressure and critical failure strain can be obtained. The strain assessment of pit defects needs to be divided into constrained and unconstrained types, and different strain criteria should be selected to evaluate them.
【作者单位】： 中国石化天然气榆济管道分公司;中石化中原天然气有限责任公司;
【分类号】：TE973
，
本文编号：2336627
[Abstract]:In order to improve the accuracy of the method for evaluating the defect and strain of the pipe pit, the damage assessment model of the pipe is established based on the ductile fracture model and damage mechanics. Combined with finite element method, the damage degree in different regions of two typical concave defects (smooth and zigzag pits) is studied, and the critical failure strain of concave defects under different pipe specifications and internal pressure is calculated. The results of numerical simulation show that the damage degree of different types of pits is different and the positions where cracks may occur are different, and the critical failure strain difference between different pipe specifications is relatively small. Due to the springback of internal pressure, the critical failure strain of unconstrained pit under different internal pressure is different, and the fitting relationship between internal pressure and critical failure strain can be obtained. The strain assessment of pit defects needs to be divided into constrained and unconstrained types, and different strain criteria should be selected to evaluate them.
【作者单位】： 中国石化天然气榆济管道分公司;中石化中原天然气有限责任公司;
【分类号】：TE973
，
本文编号：2336627
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