基于林位错强化的晶体塑性模型的稳定性缺陷及改进
发布时间：2019-03-16 16:43
【摘要】：基于林位错强化的晶体塑性有限元模型物理意义清晰简洁,具有广泛的应用。然而,只考虑林位错强化的模型忽略了共面位错之间的相互作用,导致模拟结果常常出现异常的扭曲失稳现象。针对以上问题,通过分析位错之间的相互作用,在林位错强化模型中引入自硬化作用对模型进行改进。对改进前后两个模型模拟单晶体沿单个和多个方向拉伸的变形模式以及冷轧铝板剪切带的形成特征进行了比较。结果显示,对于单晶单滑移,两个模型的稳定性表现一致;但是对于单晶多滑移,改进前的模型出现了扭曲失稳,而引入自硬化的改进模型对于多滑移系的模拟符合真实情况,并改善了模型的稳定性问题。对于冷轧铝板发生剪切变形时剪切带的形成特征,林位错强化模型的不稳定性放大了材料的失稳变形,模型的低稳定性和材料的变形失稳叠加,导致预测的结果失稳程度过高;而引入自硬化作用的改进模型改善了稳定性问题,可以真实地反映材料本身的失稳。
[Abstract]:The crystal plastic finite element model based on forest dislocation strengthening has a clear and concise physical meaning and is widely used. However, the model only considering forest dislocation strengthening ignores the interaction between coplanar dislocations, resulting in abnormal distortion and instability of simulation results. In view of the above problems, the self-hardening effect is introduced into the forest dislocation strengthening model to improve the model by analyzing the interaction between dislocations. The deformation modes of single crystal drawing along single and multiple directions and the formation characteristics of cold rolled aluminum sheet shear strip were compared before and after the modified two models were used to simulate the deformation of single crystal in single and multiple directions. The results show that the stability of the two models is the same for single crystal slip. However, for single-crystal multi-slip, the improved model is distorted and unstable, and the self-hardening model is introduced to simulate the multi-slip system in accordance with the real situation, and the stability of the model is improved. For the formation characteristics of shear band during shear deformation of cold rolled aluminum sheet, the instability of the forest dislocation strengthening model magnifies the instability deformation of the material, the low stability of the model and the superposition of the deformation instability of the material lead to the instability degree of the predicted result being too high. An improved self-hardening model is introduced to improve the stability problem, which can truly reflect the instability of the material itself.
【作者单位】： 上海交通大学材料科学与工程学院;
【基金】：国家自然科学基金资助项目(22451471107E0108)
【分类号】：TG111.2
本文编号：2441756
[Abstract]:The crystal plastic finite element model based on forest dislocation strengthening has a clear and concise physical meaning and is widely used. However, the model only considering forest dislocation strengthening ignores the interaction between coplanar dislocations, resulting in abnormal distortion and instability of simulation results. In view of the above problems, the self-hardening effect is introduced into the forest dislocation strengthening model to improve the model by analyzing the interaction between dislocations. The deformation modes of single crystal drawing along single and multiple directions and the formation characteristics of cold rolled aluminum sheet shear strip were compared before and after the modified two models were used to simulate the deformation of single crystal in single and multiple directions. The results show that the stability of the two models is the same for single crystal slip. However, for single-crystal multi-slip, the improved model is distorted and unstable, and the self-hardening model is introduced to simulate the multi-slip system in accordance with the real situation, and the stability of the model is improved. For the formation characteristics of shear band during shear deformation of cold rolled aluminum sheet, the instability of the forest dislocation strengthening model magnifies the instability deformation of the material, the low stability of the model and the superposition of the deformation instability of the material lead to the instability degree of the predicted result being too high. An improved self-hardening model is introduced to improve the stability problem, which can truly reflect the instability of the material itself.
【作者单位】： 上海交通大学材料科学与工程学院;
【基金】：国家自然科学基金资助项目(22451471107E0108)
【分类号】：TG111.2
【相似文献】
相关期刊论文 前6条
1 洪连山;;钢管冷形变位错强化遗传工艺的研究[J];钢铁;1987年05期
2 李鸿美;张慧杰;孙力军;包耀宗;;超低碳钢的强化机制研究[J];稀有金属;2010年S1期
3 许晓静;宋涛;范真;张振强;罗勇;张允康;刘云辉;;含Sc 2099型铝锂合金的组织和位错强化[J];稀有金属材料与工程;2012年S2期
4 戴丽娟;吴大风;;低碳微合金化钢强度提高分析[J];包头职业技术学院学报;2004年03期
5 赵杰;徐海峰;时捷;李箭;蒲健;曹文全;;细晶强化和位错强化对中锰马氏体钢的强化作用[J];钢铁;2012年08期
6 ;[J];;年期
，本文编号：2441756
本文链接：https://www.wllwen.com/kejilunwen/jiagonggongyi/2441756.html
