含预制裂纹陶瓷圆盘劈裂破坏的离散元模拟  

Discrete Element Simulation of Splitting Failure of Ceramic Disk withPrefabricated Crack

作　　者：杨玲[1] 任会兰[1] 赵涵 YANG Ling;REN Huilan;ZHAO Han(State Key Laboratory of Explosive Science and Technology,Beijing Institute of Technology,Beijing 100081,China)

机构地区：[1]北京理工大学爆炸科学与技术国家重点实验室,北京100081

出　　处：《高压物理学报》2023年第5期124-134,共11页Chinese Journal of High Pressure Physics

基　　金：国家自然科学基金(12072028)。

摘　　要：为研究氧化铝陶瓷在冲击载荷作用下的裂纹演化过程,对平台圆盘陶瓷开展动态巴西劈裂的离散元数值计算研究。利用离散元颗粒流软件建立陶瓷试件冲击加载实验的数值计算模型,分析了不同倾角(预制裂纹与加载方向的夹角)的试件在冲击载荷下的裂纹演化过程和破坏形式,并结合复合型裂纹尖端的应力场分布分析了翼型裂纹起裂和扩展规律。研究结果表明:平台圆盘试件的裂纹首先产生于中心部位,之后次生裂纹从圆盘边缘处萌生扩展,试件最终呈现拉伸破坏模式;离散元模拟结果与基于分离式霍普金森压杆装置的动态巴西劈裂的实验现象吻合;预制裂纹倾角为0°~60°时,改变倾角可以产生介于Ⅰ型与Ⅱ型裂纹之间的复合型裂纹,试件上主裂纹从预制裂纹尖端处成核扩展,表现为翼型裂纹扩展类型(扩展的曲率逐渐趋于零);试件裂纹的起裂角度随着预制裂纹倾角的增加而增大,起裂应力呈现先降低后升高的趋势;当预制裂纹倾角为30°时,试件最易发生开裂。To investigate the alumina ceramics’crack evolution process under impact loading,a numerical simulation of dynamic Brazilian splitting for platform disc ceramics was carried out by the discrete element method.The discrete element particle flow software was adopted to establish the numerical simulation model of ceramic specimens in impact loading experiments.The crack evolution process and failure mode of specimens with different inclination angles(the angle between the prefabricated crack and the loading direction)under impact loading were analyzed.Combined with the stress field distribution at the tip of mixed mode crack,the initiation and propagation laws of wing crack were analyzed.The results show that the cracks in the platform disc specimen are produced in the center firstly,then the secondary cracks sprouted and expanded from the disc edge.The specimen finally shows a tensile damage pattern.The results of the discrete element simulations are consistent with the experimental phenomena of dynamic Brazilian splitting based on the SHPB device.When the inclination angle of the prefabricated crack is 0°~60°,changing the inclination angle can produce a mixed crack mode between typeⅠcrack and typeⅡcrack.And the main crack on the specimen is nucleated from the tip of the prefabricated crack and exhibits a winged crack extension type(the curvature of the extension tapers to zero).With the increase of the inclination angle of the prefabricated crack,the crack initiation angle increases,and the crack initiation stress shows a trend of decreasing firstly and then increasing.The specimens are most susceptible to cracking when the prefabricated crack inclination is 30°.

关 键 词：氧化铝陶瓷 动态响应 预制裂纹 离散元 翼型裂纹 

分 类 号：O347[理学—固体力学] O346.1[理学—力学]