应变率对红砂岩渐进破坏过程和特征应力的影响

为了深入研究脆性岩石的渐进破坏过程，利用RMT-150C型岩石力学试验系统对产自鲁南地区的一种红砂岩进行了系统的力学性质试验研究，得出该类型砂岩试样在不同应变率条件下的力学表现。将试件的渐进破坏过程通过特征应力分为裂纹闭合阶段、线弹性变形阶段、裂纹起裂和稳定扩展阶段以及裂纹不稳定扩展阶段，通过对应力-应变曲线、轴向变形刚度、体积应变曲线和裂纹体积应变等数据的分析，以及采用动点回归技术确定了试样的起裂应力和致损应力，并进一步研究了该类红砂岩的渐进破坏过程及红砂岩峰值强度、起裂应力等参数和应变率之间的关系。试验结果表明，随着应变率的增加，红砂岩试样的峰值强度先降低后提高，起裂应力及致损应力与峰值强度的比值均有所降低。分析了红砂岩峰值强度变化的物理机制并给出了解释，研究了应变率对红砂岩渐进破坏过程的影响

Influence of strain rate on progressive failure process and characteristic stresses of red sandstone

In order to investigate the progressive failure process of brittle rock,the mechanical properties of red sandstone from south area of Shandong province are studied by the RMT-150C rock mechanical experimental system.The stress-strain curves of samples under different strain rates are recorded.The deformation and progressive failure process of rock samples is divided into several stages,including crack closure stage,linear elastic deformation stage,crack initiation and stable crack growth stage and unstable ...