为了研究不同微结构陶瓷材料的冲击破坏特征,以从微结构角度出发、描述陶瓷材料非弹性变形和断裂行为的Deshpande-Evan模型为基础构建本构模型,计算了无约束条件下材料的应力状态.为了验证改进模型的有效性,将VUMAT子程序编程方法将与ABAQUS有限元软件相结合,并将其应用于典型陶瓷材料(YAG透明陶瓷)冲击破坏过程的分析模拟.采用改进模型分析应变率、应力三轴度、晶粒尺寸及初始缺陷分布密度对YAG透明陶瓷动态力学行为和损伤演化机制的影响规律.结果表明:随着晶粒尺寸和裂纹分布密度的增加,YAG透明陶瓷破坏程度随之加剧,完全损伤区域面积也随之增加,晶粒尺寸对YAG透明陶瓷宏观破坏特征的影响程度要大于裂纹分布密度;YAG透明陶瓷失效强度以及断裂应变随着晶粒尺寸以及初始缺陷分布密度的增大而减小;随着应变率不断增加,YAG透明陶瓷在不同晶粒尺寸以及初始缺陷分布密度下的峰值应力和断裂应变均随之增加;裂纹扩展速度会随着晶粒尺寸的增加呈现出先增加而后平缓的趋势,裂纹扩展速度与初始缺陷分布密度系数成线性关系.改进模型可以描述YAG透明陶瓷微结构对其宏观破坏特征的影响,为进一步分析微结构对陶瓷材料宏观破坏特征的影响提供支撑.
In order to study the impact failure characteristics of ceramic materials with different microstructures,a constitutive model was constructed based on the Deshpande-Evan model which describes the inelastic deformation and fracture behavior of ceramic materials from the perspective of microstructure and the stress state of the material is calculated without considering the constraint condition.In order to verify the validity of the improved model,VUMAT subroutine programming method was used to combine it with ABAQUS finite element software,and it was applied to the analysis and simulation of the impact failure process of typical ceramic materials(YAG transparent ceramics).The effects of strain rate,stress triaxiality,grain size and crack distribution density on the dynamic mechanical behavior and damage evolution mechanism of YAG transparent ceramics were analyzed by using the improved model.The results show that with the increase of grain size and crack distribution density,the damage degree of YAG transparent ceramics increases,and the area of complete damage area increases.The influence of grain size on the macroscopic failure characteristics of YAG transparent ceramics is greater than that of crack distribution density.The failure strength and fracture strain of YAG transparent ceramics decrease with the increase of grain and crack distribution density.With the increase of the strain rate,the peak stress and fracture strain of YAG transparent ceramics under the influence of different factors(grain size as well as initial defect distribution density)increase.With the increase of grain size,the crack propagation speed of YAG transparent ceramics increases first and then flattens out,which is linearly related to the crack distribution density coefficient.The improved model can describe the influence of YAG transparent ceramic microstructure on its macroscopic failure characteristics,and provide support for further analysis of the influence of microstructure on the macroscopic failure characteristics of ceramic materials.
刘慕皓;张先锋;谈梦婷;包阔;韩国庆;李逸;孙伟境
南京理工大学机械工程学院,江苏南京 210094北京机电工程总体设计部,北京 100854
力学
含损伤本构;陶瓷材料;冲击破坏;YAG透明陶瓷;微结构特征
constitutive model involving damage factor;ceramic materials;impact failure;YAG transparent ceramics;microstructure characteristics
《爆炸与冲击》 2024 (001)
陶瓷/梯度金属泡沫复合装甲抗侵彻协同变形机制及界面击溃效应研究
60-76 / 17
国家自然科学基金(12102200,12141202);江苏省自然科学基金(BK20210320)
10.11883/bzycj-2023-0237
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