微孔洞有核长大损伤演化模型研究  

Study on a nuclear grown up damage evolution model of microvoids

作　　者：蒋东[1,2] 李永池[2] 杨建民[1] 高洪亮[1] 周刚[3] 

机构地区：[1]北京航天长征飞行器研究所,北京100076 [2]中国科学技术大学近代力学系,合肥230026 [3]西北核技术研究所,西安710000

出　　处：《应用力学学报》2018年第2期228-233,共6页Chinese Journal of Applied Mechanics

基　　金：973项目(6133120402);博士后科学基金(2014M560829)

摘　　要：针对材料的层裂问题,从细观角度出发,提出微孔洞有核长大损伤演化模型假说。该模型包含损伤开始、演化和终止三个阶段,共有4个材料参数,分别是代表损伤开始发展的阈值应力的σ_0,损伤演化时损伤率对超阈值应力的依赖指数λ,损伤终止时材料发生层裂时的极限损伤D_c,和损伤持续的时间参数Ψ。通过对D6AC钢和45钢层裂实验进行计算分析,验证了本文提出的损伤演化模型假说的合理性。并结合试验,给出了模型中4个材料参数物理内涵、取值方法及影响规律。损伤发展的过程量λ对损伤影响最大,表明损伤演化过程并非简单的能量累积,其次是损伤阈值应力σ_0,极限损伤D_c和损伤持续的时间参数Ψ对损伤影响最小。To study the microvoid damage, the necleation and growth damage evolution model hypothesis is put forwarded, combined with damage constitutive theories. The model consists of three stages, that is, damage initiation, evolution and termination. Meanwhile, this model has four material parameters, which are representative of the damage threshold stress σ_0, spallation time-related parameter Ψ, the damage rate on the over-threshold stress dependency index λ and the ultimate damage D_c. Through the calculation and simulation of 45 steel and D6 AC steel spalling experiments, the practicability of micro-hole nucleation and long-scale damage evolution model is proved. Combined with the experiments, the physical mechanisms, the method to determine values and the influential rule of the four material parameters in the model are given. The damage rate on the over-threshold stress dependency index λ is the most influential factor, which indicates that the damage evolution process is not a simple energy accumulation, followed by the damage threshold stress σ_0. The ultimate damage D_c and the duration of the damage parameters Ψ are the least factors on the damage.

关 键 词：爆炸力学 损伤演化 平板撞击 层裂 

分 类 号：O385[理学—流体力学]