东南大学学报（自然科学版）2025，Vol.55Issue(4)：982-991,10.DOI:10.3969/j.issn.1001-0505.2025.04.007
低碳钢延性断裂机理多尺度研究和模拟
Multi-scale investigation and simulation on ductile fracture mechanism of mild steel
摘要
Abstract
Ductile fracture of metallic materials exhibits characteristic multi-scale features.To investigate the ductile fracture mechanism of mild steel,in-situ microscale computed tomography(CT)and scanning electron microscopy techniques were employed to reconstruct three-dimensional microstructural evolution of Q235B steel from the initial state to ductile fracture under uniaxial tensile loading.The high-precision two-dimensional fracture surface morphology was observed.The void evolution mechanism was revealed through experiments.A method of calibrating Gurson-Tvergaard-Needleman(GTN)model parameters at mi-croscale was proposed.Multi-scale simulation and verification were conducted.The results show that both the volume and number of voids in Q235B steel are relatively small before necking,while after necking void evo-lution becomes significant and porosity exhibits an exponential increase in the necked region,ultimately caus-ing fracture.During void evolution,continuous void nucleation and growth contribute to an increase in poros-ity.There are two modes of void coalescence,including intervoid necking and shearing,eventually leading to characteristic cup-cone fracture surfaces.The GTN model can accurately predict the macroscopic ductile frac-ture behavior of Q235B steel,with a fracture strain error of 0.6%.The simulation results of porosity evolution at the microscale are in good agreement with the experimental data.关键词
Q235钢/延性断裂/多尺度/空穴演化/GTN模型Key words
Q235 steel/ductile fracture/multi-scale/void evolution/Gurson-Tvergaard-Needleman(GTN)model分类
建筑与水利引用本文复制引用
刘韬,周昌风,陈波,陈建兴,贾良玖..低碳钢延性断裂机理多尺度研究和模拟[J].东南大学学报（自然科学版）,2025,55(4):982-991,10.基金项目
国家自然科学基金面上资助项目(52178499) （52178499）
中央高校基本科研业务费专项资金资助项目. （）
