单轴压缩下含孔脆性材料的力学行为研究

Study on mechanics behavior of containing holes in brittle material subjected to uniaxial compression

运用材料破裂过程分析MFPA2D系统,在单轴压缩条件下对含单孔和双孔脆性材料破坏过程进行数值模拟。结果表明:原始的萌生裂纹不一定是最后形成宏观贯通破坏的主裂纹。岩石等脆性材料破坏的局部化特征,说明非均匀性是岩石类脆性材料发生局部破裂的根本原因。分析了孔的分布对材料强度以及破坏模式的影响,并给出破坏过程的应力-应变关系。指出了有的孔洞分布会增加应力的集中程度,而有的孔洞分布可以降低应力集中。数值模拟与试验结果具有较好的一致性。

A newly developed numerical approach MFPA^2D （material failure process analysis）Code is presented to simulate the failure process of brittle material containing single hole or double holes under uniaxial compression. Numerical simulation results show that initial cracks are not always the leading cracks which result in the ultimate macroscopical perforation failure. And brittle materials have a localization characteristic when they damage. It is also shown that nonhomogeneity is the essential reason of brittle material＇s local failure. The influence of hole distribution on the material strength and failure mode is studied. Stress-strain curves of failure process for models are provided. The material strength decreases 50% if it contains a single hole or double holes. It is indicated that some hole distribution can increase the stress concentration and some hole distribution can decrease the stress concentration. The numerical simulation results are consistent with the experimental results.