摘要
运用Holmquist-Johnson-Cook(HJC)本构模型对混凝土的SHPB实验进行了数值模拟。解决了罚函数算法中罚因子合理数值的选取问题。利用模拟结果按SHPB两波法重构了试样的应力应变曲线。分析了混凝土材料的SHPB实验得到应力应变曲线的有效段范围和各段的力学规律。通过比较实际混凝土材料SHPB实验和数值模拟得到的应力应变曲线,发现两者体现的力学行为很相似,即HJC模型是描述该类材料的一种合理本构模型。模拟了试样不同平行度公差下的SHPB实验,发现在一定应变率范围内其影响程度远大于试样应力(应变)不均匀性。
The split Hopkinson pressure bar （SHPB） tests for concrete were numerically simulated by using the Holmquist-Johnson-Cook （HJC） constitutive model. The contact stiffness in the penalty function algorithm was reasonably determined. The stress-strain curves of the concrete specimens were reconstructed from the simulated results by applying the two-wave method used in the data processing of the SHPB tests. The effective ranges of the stress-strain curves obained in the SHPB tests and their mechanical regularity were analyzed. By comparing the stress-strain curve obtained from the SHPB test with the reconstructed curve from the numerical simulation, it can be found that the mechanical behaviors of the two curves are similar. It is verified that the HJC model is a reasonable constitutive model for describing the concrete materials. Numerical simulations were carried out for the SHPB tests of the concrete specimens with different tolerances in parallel. The simulated results show that the tolerances in parallel of specimens affect the SHPB tests much more remarkably than the stress（strain） nonuniformity in a certain strain-rate range.
出处
《爆炸与冲击》
EI
CAS
CSCD
北大核心
2009年第2期137-142,共6页
Explosion and Shock Waves
