应力三维度在层裂中的应用初探  

PRELIMINARY PROBE ON THE APPLICATION OF STRESS TRIAXIALITY IN SPALLING FIELDS

作　　者：张世文 刘仓理 李庆忠 

机构地区：[1]流体物理研究所冲击波物理与爆轰物理实验室,四川绵阳621900

出　　处：《工程力学》2012年第4期60-65,共6页Engineering Mechanics

基　　金：国家自然科学基金项目(10772165);中国工程物理研究院"双百人才"基金项目(2005R0802)

摘　　要：探讨了应力三维度用于层裂分析的必要性和可能性。结合体胞模型的尺寸无关性特征,讨论了高应变率下高应力三维度对孔洞扩展影响的数值模拟方法。在此基础上,对轴对称体胞在不同的应力三维度下孔洞扩展进行了数值模拟。结果表明:宏观定义的等效应力-等效应变关系、孔洞体积分数与球应力关系不存在单值对应关系,它与应力三维度密切相关,因而,以应变等价原理为基石构建的含损伤本构或者状态方程在推广到其它应力状态时存在一定的局限,特别是以空心球模型在球对称应力加载下获得的含损伤本构和状态方程不能用于其它非球对称应力状态下的损伤演化。We investigate the necessity and possibility about the application of the stress triaxiality used for the analysis of spalling fields.Combining with the size-independence of a cell model,the numerical simulation method,employed for the implementation of void growth under a high stain rate and high stress triaxiality,is discussed.On this basis,we perform the simulation of void growth under different stress triaxiality in the axial symmetry cell.The calculation results indicate that the macroscopic equivalent stress vs.equivalent strain relation and void volume fraction vs.spherical stress relation are not unique correspondence,but depend on the stress triaxiality.Therefore,the damage constitutive or equation of states in specific stress states based on the strain equivalence principle could not be appropriate for applying to other stress states,e.g.the obtained damage constitutive and equation of states by acting on the spherical stress in the hollow sphere cell model cannot be described for the non-spherical stress states.

关 键 词：冲击动力学 应力三维度 层裂 应变等价原理 空心球模型 

分 类 号：O346.1[理学—固体力学] O346.5[理学—力学]