3D-Simulation of ductile failure in two-phase structural steel with heterogeneous microstructure
3D-Simulation of ductile failure in two-phase structural steel with heterogeneous microstructure
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DOI：
10.1016/j.engfracmech.2009.08.011
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发表时间：
2010
影响因子：
5.4
通讯作者：
M. Ohata;M. Suzuki;A. Ui;F. Minami
中科院分区：
文献类型：
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作者：
M. Ohata;M. Suzuki;A. Ui;F. Minami
本研究的目的是开发一种模拟方法来预测铁素体-珠光体双相钢的微观组织形态对韧性失效抗力结构性能的影响。这是基于一个明确的损伤机制，以控制韧性开裂，重点是强度的微观结构的不均匀性。在两相界面附近的低强度侧大量的微孔洞形核与应力/应变的局部化被发现控制韧性开裂。根据这一实验结果，我们开发了细观尺度的三维模型，以再现感兴趣的实际两相钢的微观组织形态，分析应力/应变局部化行为与组织的不均匀性。此外，提出了包含微孔洞形核塑性势的损伤演化模型，可以模拟韧性裂纹的形核以及随后的生长和连接。采用细观三维结构有限元模型和损伤演化模型对双相结构钢的延性开裂行为进行了数值模拟。数值模拟了外加三轴应力状态对延性开裂临界宏观应变的影响以及随应力三轴度的增大而减小的损伤演化行为。
The effort of this study is to develop a simulation method to predict the effect of micro-structural morphology in two-phase steel, Ferrite–Pearlite steel, on structural performance in terms of ductile failure resistance. This is based on a clarification of a damage mechanism to control the ductile cracking with focusing on the heterogeneity in strength of microstructure. The large number of micro-voids nucleation at lower strength side near two-phase boundary associated with the localization of stress/strain is found to control ductile cracking. According to this experimental result, we develop meso-scale 3D-model to reproduce micro-structural morphology of practical two-phase steel of interest for analyzing stress/strain localization behaviors associated with heterogeneity of microstructure. Moreover, damage evolution model including plastic potential to nucleate micro-void is proposed, so that ductile crack nucleation and subsequent growth and linking could be simulated. The ductile cracking behavior for two-phase structural steel is simulated by means of the developed meso-scale 3D micro-structural FE-model together with the damage evolution model. The effect of applied triaxial stress state on critical macro-strain for ductile cracking as well as damage evolution behavior, in which the critical strain could be decreased with increasing stress triaxiality, is numerically predicted.