单调荷载下钢材延性断裂损伤因子模型及参数校准

发布时间：2018-05-11 02:03

本文选题：Q钢 + 延性断裂　；参考：《东南大学学报(自然科学版)》2017年05期

【摘要】：为提高钢材断裂模型的通用性和实时性,采用延性损伤因子概念,分别建立了基于VGM的VGM-DDF断裂模型和基于Johnson-Cook的JC-DDF断裂模型.结合不同槽口半径光滑圆棒试件的单向拉伸试验和有限元分析,研究了不同试件加载过程中应力三轴度和等效塑性应变的关系,并对国产Q235钢在单调荷载下延性断裂损伤因子模型参数进行了校准.采用校准后的断裂模型计算了各试件断裂损伤因子值,利用Abaqus软件对钢材断裂进行全过程模拟,并对不同的单元网格尺寸模型进行分析.结果表明:损伤因子模型的有效性得到验证,且JC-DDF模型离散性更小;断裂后荷载位移模拟曲线与试验曲线具有较好的吻合度;有限元单元网格尺寸影响断裂预测精度,并建议网格尺寸取0.25 mm.
[Abstract]:In order to improve the universality and real-time performance of steel fracture model, the VGM-DDF fracture model based on VGM and the JC-DDF fracture model based on Johnson-Cook were established by using the concept of ductile damage factor. Combined with uniaxial tensile test and finite element analysis of smooth round bar specimens with different groove radius, the relationship between triaxiality of stress and equivalent plastic strain during loading of different specimens is studied. The model parameters of ductile fracture damage factor of Q235 steel under monotonic load were calibrated. The fracture damage factors of each specimen were calculated by using the calibrated fracture model, the whole process of steel fracture was simulated by Abaqus software, and the different mesh size models were analyzed. The results show that the validity of the damage factor model is verified, and the JC-DDF model is less discrete, the post-fracture load-displacement simulation curve is in good agreement with the experimental curve, and the finite element mesh size affects the accuracy of fracture prediction. It is suggested that the mesh size should be 0.25 mm.
【作者单位】：东南大学混凝土及预应力混凝土结构教育部重点实验室;德州大学奥斯汀分校土木建筑和环境工程系;国网江苏省电力公司经济技术研究院;
【基金】：国家自然科学基金资助项目(51208095) 江苏省“青蓝工程”资助项目江苏省六大人才高峰资助项目(JZ-003)
【分类号】：TU391

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