X90超高强度输气钢管材料本构关系及断裂准则

发布时间：2018-07-01 08:19

本文选题：X钢管 + 应力三轴度　；参考：《石油学报》2017年01期

【摘要】：针对试制成功的X90输气钢管,进行5种不同圆棒缺口的准静态拉伸试验及应力三轴度计算,发现由于试样缺口存在,应力三轴度值增加2.43倍,断裂应变减少29%,损伤应变能降低71%。利用常规拉伸试验机和Hopkinson拉杆试验装置进行不同应变速率拉伸试验发现,应变速率对断裂应变的影响相对较小,准静态和高速状态下,差异最大约10%。基于Johnson-Cook本构和失效模型,分别建立了考虑应变率效应的X90管线钢本构模型和考虑应变率、应力三轴度的失效模型;同时,基于损伤力学理论,得到了基于塑性均匀延伸率和损伤应变能的X90管线钢断裂准则。基于材料损伤应变能密度临界值不变假设以及试验数据,得到了X90管线钢断裂特征长度与应力三轴度、试样直径之间的关系式。
[Abstract]:Based on the quasi static tensile test and stress triaxiality calculation of five different round bar notches, it is found that the stress triaxiality value increases by 2.43 times, the fracture strain decreases by 29 times, and the damage strain energy decreases by 71% because of the existence of the specimen gap. By using the conventional tensile tester and Hopkinson bar test apparatus, it is found that the strain rate has relatively little effect on the fracture strain, and the maximum difference is about 10% under quasi-static and high-speed conditions. Based on Johnson-Cook constitutive model and failure model, the constitutive model of X90 pipeline steel considering strain rate effect and failure model considering strain rate and stress triaxiality are established, respectively. The fracture criterion of X90 pipeline steel based on plastic uniform elongation and damage strain energy is obtained. Based on the assumption of the critical value of material damage strain energy density and the experimental data, the relationship between fracture characteristic length, stress triaxiality and specimen diameter of X90 pipeline steel is obtained.
【作者单位】：中国石油集团石油管工程技术研究院石油管材及装备材料服役行为与结构安全国家重点实验室;西安三环科技开发总公司;西北工业大学航空学院;中国石油西部管道公司;
【基金】：国家自然科学基金项目(No.51404294) 陕西省自然科学基金项目(2014JQ2-1004) 中国石油天然气集团公司重大科技专项(2012E-2801)资助
【分类号】：TE973

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