Rock engineering achieves the secondary stress balance through rock mass structure adjustment, where energy conversion is throughout and associated closely with rock deformation and damage. In this study, a series of triaxial compression tests were conducted on red sandstone to investigate these features. The results showed that the damage state of red sandstone specimens presented five stages under different confining pressure, corresponding to the multistage evolution characteristic of the energy conversion. In the case of the dissipation energy conversion ratio (η), it showed five stages: a gradual increase, decreasing gradually and reaching a minimum value, increasing gradually, increasing with growth rate, and accelerated growth, therein the strong nonlinearity reflected the stability and instability of the internal structure of the rock and had the basic characteristics of the mutation theory, therefore the damage state warning model was established on just that. The relation between the η and time fitted by a four-rank potential function had a fitting parameter (R²) larger than 0.9, and the bifurcation set of the η calculated by the damage state warning model had twice stages less than 0. The second stage, which occurred near the minimum value of the η and run through the plastic deformation stage, could be used to predict rock damage and fracture, and it was proven feasible by acoustic emission (AE) precursor and better than AE warning. This research can enrich the methods for identifying rock damage state and provide reference for revealing the occurrence and development mechanism of various rock instability disasters.

中文翻译：

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基于能量转换的岩石突变特征及损伤状态预警模型研究

岩石工程通过岩体结构调整实现二次应力平衡，能量转换贯穿始终，与岩石变形损伤密切相关。在本研究中，对红砂岩进行了一系列三轴压缩试验来研究这些特征。结果表明，不同围压下红砂岩试件的损伤状态呈现出5个阶段，对应了能量转换的多阶段演化特征。耗散能量转化率（η）呈现逐渐增加、逐渐减少并达到最小值、逐渐增加、随增长率增加、加速增长五个阶段，其中强非线性体现了稳定性和稳定性。岩石内部结构的不稳定性，具有突变理论的基本特征，因此建立了损伤状态预警模型。四阶势函数拟合的η与时间关系的拟合参数（ R2）大于0.9，损伤状态预警模型计算得到的η分叉集^有两个阶段小于0。发生在η最小值附近并贯穿塑性变形阶段的阶段可用于预测岩石损伤和破裂，声发射（AE）前兆证明该阶段是可行的，并且优于 AE 预警。该研究可丰富岩石损伤状态识别方法，为揭示各类岩石失稳灾害的发生、发展机制提供参考。