Determination of Johnson-Cook parameters and evaluation of Charpy impact test performance for X80 pipeline steel
Determination of Johnson-Cook parameters and evaluation of Charpy impact test performance for X80 pipeline steel
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DOI：
10.1016/j.ijmecsci.2020.105627
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发表时间：
2020-08-01
影响因子：
7.3
通讯作者：
Li, Xuyang
中科院分区：
文献类型：
--
作者：
Cao, Yuguang;Zhen, Ying;Li, Xuyang
控制材料的夏比冲击韧性是管道韧性止裂设计的关键。基于Johnson-Cook（J-C）模型的有限元方法已成为辅助材料冲击韧性实验研究的有效手段。本文通过准静态单轴拉伸试验和分离式霍普金森压杆（SHPB）试验，确定了X80管线钢J-C本构关系的模型参数和J-C破坏模型的损伤参数。采用J-C本构模型和失效模型，在确定的参数下，对夏比冲击试验进行了模拟。模拟和实验结果之间取得了合理的协议。在此基础上，研究了摆锤速度、试件宽度和撞针半径对夏比冲击试验结果的影响。结果表明：摆锤速度对夏比冲击试验结果的影响很小;最大冲击力和冲击吸收能量均与试样宽度呈高度线性关系;夏比冲击试验对撞针的几何形状很敏感，2 mm撞针测得的结果明显小于8 mm撞针测得的结果。在此基础上，建立了亚尺寸试件与标准全尺寸试件冲击吸收能量的相关模型，建立了两种撞击器试验结果的转换规律。本文的研究方法和结果可为高钢级管线钢的动态性能研究、冲击动力学设计、管道安全运行和风险评估提供参考。
Controlling the Charpy impact toughness of materials is the key to the ductile fracture arrest design of pipelines. The finite element method based on Johnson-Cook (J-C) model has become an effective method to assist the experimental study of material impact toughness. In this paper, model parameters of J-C constitutive relation and damage parameters of J-C failure model for X80 pipeline steel have been determined experimentally from quasistatic uniaxial tension tests and Split Hopkinson Pressure Bar (SHPB) tests. Charpy impact test has been simulated using J-C constitutive and failure models with the determined parameters. Reasonable agreements between the simulation and experimental results have been achieved. On this basis, the effects of the pendulum velocity, specimen width and striker radius on Charpy impact test results are studied. The results show that pendulum velocity has negligible influence on Charpy impact test results; the maximum force and impact absorbed energy both have a highly linear relationship to specimen width; Charpy impact test is sensitive to striker geometry, the results measured by 2 mm-striker are obviously smaller than those of 8 mm-striker. Based on the above researches, the impact absorbed energy correlation model between sub-size specimens and standard full-size specimens, the test results transformation rules of the two strikers are established. The methods and results presented in this paper will provide references for dynamic behavior study, impact dynamic design, pipeline safety operation and risk assessment of high-grade pipeline steel.