论文部分内容阅读
从内能角度分析发生蠕变的机制,基于应变能理论,采用Perzyna黏塑性理论与西原正夫元件模型相结合,建立了一种能描述衰减蠕变、稳定蠕变和加速蠕变3个阶段全过程的蠕变统一本构模型。该模型考虑了应力状态对加速蠕变的影响,通过定义加速蠕变临界应变能密度值可以有效判断加速蠕变发生时刻,并在统一蠕变本构模型基础上进行简化,采用Drucker-Prager(D-P)屈服准则结合相关联流动法则,用过屈服应力比反映加速阶段蠕变应变速率变化,建立了一个实用的能预测加速蠕变并能反映蠕变3阶段全过程的简化蠕变本构模型,结果表明,数值模拟结果与试验数据基本吻合,研究成果为岩石蠕变断裂过程研究提供了一种新的思路。
From the perspective of internal energy, the creep mechanism is analyzed. Based on the theory of strain energy, Perzyna’s theory of viscoplasticity is combined with Nishihara’s element model to establish a method that can describe the three stages of decay creep, stable creep and accelerated creep Process Creep Unified Constitutive Model. The model considers the effect of stress state on accelerating creep. By defining the value of critical strain energy density of accelerating creep, the accelerating creep moment can be effectively judged and simplified based on the unified creep constitutive model. Drucker-Prager ( DP) yield criterion and the associated flow law, the change of creep strain rate in the accelerated phase is reflected by the yield-stress ratio, and a simplified simplified creep constitutive model that can predict accelerated creep and reflect the whole process of creep 3-stage is established The results show that the numerical simulation results are in good agreement with the experimental data and the research results provide a new idea for the study of rock creep rupture process.