Modification of Visco Statistical Crack Mechanics for PBXs
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摘要: 基于描述PBX炸药本构关系的粘弹性统计微裂纹模型(Visco-SCRAM)，通过修正其微裂纹方向矢量的取值范围、初始缺陷尺寸和体量本构关系，得到模型的改进形式。将改进的模型嵌入有限元程序中，开展PBX炸药JO-9159的平板撞击实验数值模拟研究，讨论了微裂纹数密度参数对计算结果的影响。结合实测曲线，对模型改进前、后的计算结果进行对比和分析。结果表明，改进的模型能够更合理地描述低速冲击下PBX炸药的损伤和破坏。
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关键词:
- PBX炸药 /
- 粘弹性统计微裂纹模型 /
- 微裂纹数密度 /
- 数值模拟
Abstract: Based on the Viscose-Statistical Crack Mechanics (Visco-SCRAM) model describing the dynamic response of PBXs', a modified model is obtained through changing the value scope of the direction vector of crack surface, the value of initial flaw size and the volumetric constitutive relation.Then the new model is applied in a finite element program.During the simulation process of the plate impact experiment for PBX JO-9159, the influence of crack number density parameter N0 is analyzed.Combined with the experimental data, the results simulated by the original and modified models are compared and analyzed.It is concluded that the modified model describes the damage and failure of PBXs under low-velocity impact more reasonably.-
Key words:
- PBX /
- Visco-SCRAM /
- crack number density /
- numerical simulation
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图 3 不同N0取值时模拟所得纵向应力曲线
Figure 3. Simulated results of longitudinal stress curves under different N0 values
图 5 模型改进前、后数值模拟结果对比
Figure 5. Comparison between simulated results of different models
表 1 改进的Visco-SCRAM模型输入参数
Table 1. Constitutive model parameters for modified Visco-SCRAM model
ρ0/(g/cm3) G0/(GPa) K0/(GPa) ν 0/(μm) vmax/(km/s) m KIC/(MPa·m1/2) G(1)/(GPa) 1.86[6] 3.235[4] 4.782 0.224[6] 30[6] 0.3[6] 10[6] 0.24[6] 0.944[4] G(2)/(GPa) G(3)/(GPa) G(4)/(GPa) G(5)/(GPa) 1/τ(1)/(s-1) 1/τ(2)/(s-1) 1/τ(3)/(s-1) 1/τ(4)/(s-1) 1/τ(5)/(s-1) 0.173 8[4] 0.521 2[4] 0.908 5[4] 0.687 5[4] 0[4] 7.32×103[4] 7.32×104[4] 7.32×105[4] 2.0×106[4] 
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