叶继红, 范志鹏. 基于微观机制的复杂应力状态下钢材韧性断裂行为研究[J]. 工程力学, 2021, 38(5): 38-49. DOI: 10.6052/j.issn.1000-4750.2020.06.0394
引用本文: 叶继红, 范志鹏. 基于微观机制的复杂应力状态下钢材韧性断裂行为研究[J]. 工程力学, 2021, 38(5): 38-49. DOI: 10.6052/j.issn.1000-4750.2020.06.0394
YE Ji-hong, FAN Zhi-peng. DUCTILE FRACTURE BEHAVIOR OF STEEL UNDER COMPLEXSTRESS STATE BASED ON MICROSCOPIC MECHANISM[J]. Engineering Mechanics, 2021, 38(5): 38-49. DOI: 10.6052/j.issn.1000-4750.2020.06.0394
Citation: YE Ji-hong, FAN Zhi-peng. DUCTILE FRACTURE BEHAVIOR OF STEEL UNDER COMPLEXSTRESS STATE BASED ON MICROSCOPIC MECHANISM[J]. Engineering Mechanics, 2021, 38(5): 38-49. DOI: 10.6052/j.issn.1000-4750.2020.06.0394

基于微观机制的复杂应力状态下钢材韧性断裂行为研究

DUCTILE FRACTURE BEHAVIOR OF STEEL UNDER COMPLEXSTRESS STATE BASED ON MICROSCOPIC MECHANISM

  • 摘要: 韧性断裂是钢材最常见的破坏形式,研究钢材韧性断裂机理并准确预测钢材韧性断裂行为具有重要的理论意义和工程实用价值。基于微观机制的断裂预测方法对研究钢材韧性断裂行为有较好的适用性。该文基于体胞模型空穴演化机理改进了现有的韧性断裂模型,校核了Q345钢材断裂模型参数。此外,在韧性断裂模型中引入损伤因子,以考虑应力状态在加载过程中的变化,使断裂模型能准确描述每一加载时刻的累积损伤值。文末采用Fortran语言将断裂模型编写USDFLD子程序,并将其植入有限元程序ABAQUS,对一组十字型刚节点试件单轴拉伸试验进行数值模拟。结果表明,该断裂模型在拉-剪复合应力状态下具有良好的预测精度,且能够准确捕捉钢材断裂起始位置及裂缝扩展路径。该文改进的韧性断裂模型也可用于其它韧性金属材料断裂预测分析。

     

    Abstract: Ductile fracture is the most common form of steel damage. It is of a great theoretical significance and practical value to study the toughness fracture mechanism of steel and to accurately predict the ductile fracture behavior of steel. The fracture prediction method based on microscopic mechanism has good applicability for studying the toughness fracture behavior of steel. The existing ductile fracture model is improved based on the void evolution mechanism of the somatic cell model, and the parameters of the Q345 steel fracture model are verified. In addition, the damage factor is introduced into the ductile fracture model to consider the change of stress state during loading, thusly the fracture model can accurately describe the cumulative damage value at each loading moment. At the end of the article, Fortran language is used to compile the fracture model into USDFLD subroutine, and it is inserted into the finite element program ABAQUS to numerically simulate the uniaxial tensile test of a group of cross-type rigid joint specimens. The results show that the fracture model has good prediction accuracy under the tensile-shear composite stress state, and can accurately capture the steel fracture start position and crack propagation path. The improved ductile fracture model can also be used for the fracture prediction analysis of other ductile metal materials.

     

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