基于键基近场动力学理论的单裂纹圆孔板冲击破坏研究  

THE IMPACTED DAMAGE STUDY OF A SINGLE CLEAVAGE DRILLED COMPRESSION SPECIMEN BASED ON BOND-BASED PERIDYNAMICS

作　　者：刘宁[1] 胡梦凡 周飞[1] LIU Ning;HU Meng-fan;ZHOU Fei(College of Mechanical Engineering,Nanjing University of Science and Technology,Nanjing,210094,China)

机构地区：[1]南京理工大学机械工程学院,南京210094

出　　处：《工程力学》2020年第12期9-17,共9页Engineering Mechanics

基　　金：冲击波物理与爆轰物理重点实验室基金项目(6142A0302020517)。

摘　　要：基于键基近场动力学理论,建立分离式霍普金森杆冲击单裂纹圆孔板动力学模型,其中霍普金森杆用一维PD模型、单裂纹圆孔板用二维PD模型描述,采用短程斥力模型描述碰撞过程,模拟冲击压缩条件下单裂纹圆孔板动态破坏行为。通过试样端面受力分析得到端面载荷的V形分布规律,解决了传统实验-数值研究法在端面加载上的局限性。研究不同入射速度下试件裂纹的扩展过程和破坏模式,准确捕获了裂纹起裂、止裂及二次起裂时间。根据键基近场动力学理论下材料动态应力强度因子计算方法,求得裂纹的起裂韧度,为材料动态断裂韧度计算提供了新的途径。A dynamic analytical model is built for a single cleavage drilled compression specimen(SCDC)impacted by a split Hopkinson pressure bar based on bond-based peridynamics,in which the Hopkinson bar is simplified as 1D model and the specimen is described as 2D model.The repelling short-range force is used for modeling the impact process.The dynamic failure behaviors of the single cleavage drilled compression specimen are studied using the model.The force analysis indicates that:the stress distribution on the end faces of the specimen is showed as a V-shape pattern and it well solves the limitation of the end face loading way of the traditional experimental-numerical method.Then the crack propagation processes and failure modes are studied under different impact velocities.It shows that:the numerical model accurately predicts the times of the crack initiation,arrest and the secondary crack initiation.Simultaneously,the crack initiation toughness at the crack tip is calculated according to the algorithm of dynamic stress intensity factor in bond-based peridynamics,which provides a new method for the dynamic fracture toughness analysis of materials.

关 键 词：近场动力学 压缩单裂纹圆孔板 分离式霍普金森杆 裂纹扩展 动态断裂韧度 

分 类 号：TU45[建筑科学—岩土工程]