层裂损伤孔洞增长模型参数的确定方法及其应用  

Method of determining parameters of void growth damage model and its application to simulation of spall test

作　　者：张凤国[1] 刘军[1] 何安民[1] 王裴[1] 王昆 周洪强[1] 赵福祺 Zhang Feng-Guo;Liu Jun;He An-Min;Wang Pei;Wang Kun;Zhou Hong-Qiang;Zhao Fu-Qi(Institute of Applied Physics and Computational Mathematics,Beijing 100094,China)

机构地区：[1]北京应用物理与计算数学研究所,北京100094

出　　处：《物理学报》2020年第20期262-268,共7页Acta Physica Sinica

基　　金：科学挑战专题(批准号:TZ2018001);国家自然科学基金(批准号:U1530261)资助的课题.

摘　　要：基于自由面速度曲线及其与层裂面处物理量变化之间的关联,考虑层裂损伤演化过程中波的传播与相互作用,进一步探讨了损伤演化过程中的临界状态,分析了孔洞增长层裂损伤模型参数所包含的物理涵义,并给出基于物理的模型参数确定方法.通过对两种典型延性金属OFHC铜和钽层裂实验结果的模拟,验证了该方法的合理性.本文给出的参数确定方法不仅可以扩展模型的适用范围,有效提高计算结果的可信度,同时,也为其他层裂损伤模型参数的确定提供了很好的借鉴作用.Spallation of ductile metal is of great importance in many scientific and engineering fields,which is due to the interaction between the incident shock waves and the reflected waves.Physically,the spallation is caused by nucleation,growth and coalescence of microvoids for ductile material.Therefore,numerical simulation of spall process usually involves theoretical model of void growth.However,due to the limited knowledge of microvoid properties,many empirical parameters are included in the void growth model,which are usually determined by comparing numerical results with experimental data.Therefore,a key problem arises in the numerical modeling of damage and spall fracture,that how the parameters of the void growth damage model can be determined.In this work,we present a theoretical method to determine the parameters based on the free surface velocity(FSV)profile.Firstly,the critical state of damage is discussed based on the relationship between characteristics of FSV and change of physical quantity in spall plane.Then,the propagation and interaction of shock waves during the evolution of spall damage are considered.Lastly,the physical meanings of the parameters of the void growth damage model are further discussed.So,based on the relation among spall strength,damage and pullback of FSV,a physics-based method to determine the parameters of the model is given.The applicability of this method is verified by the simulation of the spall experimental data on typical ductile metals OFHC copper and tantalum.The parameter-determining method given in this paper can not only expand the scope of application of the damage model and effectively improve the reliability of the calculation results,but also provide a good reference for the determination of parameters of other spall damage model.

关 键 词：延性金属 层裂损伤 孔洞增长损伤模型 参数确定 

分 类 号：O346.1[理学—固体力学]