摘要
基于钢材单轴拉伸试验,提出了关于拉伸试验数据和真实应力应变曲线的修正方法.开发了VGM模型和SMCS模型的USDFLD用户子程序,用于微观断裂模型的有限元模拟,分析了应力三轴度对等截面和非等截面构件微观断裂模型预测结果的影响.结果表明,进行等截面构件的本构曲线拟合时应同时考虑颈缩点真实应力和断裂点真实应力的修正.受应力三轴度的影响,在等截面拉伸条件下SMCS模型预测的断裂位移普遍小于VGM模型.非等截面拉伸条件下应力三轴度的变化趋势多样,SMCS模型预测两板相交构件的断裂变形量远大于VGM模型,前者为后者的3.10倍.当拉伸构件存在多个断裂危险点时,VGM模型与SMCS模型的启裂点出现于不同位置处,建议以VGM模型预测位置为准.
The modification methods of tensile test data and real stress-strain curves were proposed based on steel uniaxial tensile tests.The USDFLD subroutine of the void growth model(VGM)and the stress modified critical strain(SMCS)model was developed on ABAQUS for the finite element simulation of the micromechanical fracture model.The influence of the stress triaxiality on the prediction results of the models for uniform and non-uniform section members was analyzed.The results show that the correction of the true stress at the necking point and the true stress at the fracture point should be considered during the fitting of the constitutive curves of the equal cross-section members.Due to the influence of the stress triaxiality,the fracture displacement of the SMCS model is generally smaller than that of the VGM under the condition of uniform section tension.The trend of the stress triaxiality is various under the condition of non-uniform section tensions.The fracture deformation of the intersecting members of the two plates predicted by the SMCS model is much larger than that calculated by the VGM,and the former is 3.10 times the latter.When there are multiple fracture risk points,the crack initiation points of the VGM and the SMCS model appear at different positions,and the predicted position of the VGM is suggested to be prevail.
作者
李万润
郭赛聪
杜永峰
Li Wanrun;Guo Saicong;Du Yongfeng(Institute of Earthquake Protection and Disaster Mitigation,Lanzhou University of Technology,Lanzhou 730050,China;School of Civil Engineering,Lanzhou University of Technology,Lanzhou 730050,China;International Research Base on Seismic Mitigation and Isolation of Gansu Province,Lanzhou University of Technology,Lanzhou 730050,China)
出处
《东南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2021年第6期958-966,共9页
Journal of Southeast University：Natural Science Edition
基金
国家自然科学基金资助项目(51568041,51908266)
甘肃省减震隔震国际科技合作基地定向基金资助项目(GII2018-N04)
甘肃省土木建筑学会青年科技托举人才资助项目
兰州理工大学红柳优秀青年基金资助项目.
