贺兰山岩画典型病害损伤的声发射演化特征研究

Acoustic Emission Characteristics and Damage Analysis of Rock Uniaxial Compression in Helan Mountain

裂(隙)纹是宁夏贺兰山岩画表面完整性严重破坏的典型病害问题.本研究基于声发射原理,利用单轴压缩试验模拟岩画载体材料岩石所受荷载,分析岩画载体材料强度破坏模式,获取声发射信号特征,探究AE时空演变规律,建立基于声发射累计振铃计数的损伤演化模型.研究结果表明:岩石破坏呈现“圆锥形”,其损伤发展主要经历原生裂纹闭合、次生裂纹发育以及裂纹贯穿破坏3个演化历程;损伤演化模型的力学和物理意义明确.声发射特征与变形特征紧密相关,能够表征岩石内部损伤过程,可以用来判断岩样岩石内部(微)裂纹状态,为石质文物载体材料裂纹扩展至破裂失稳这一热点和难点问题提供解决思路.

Crack is a typical disease of serious damage to the surface integrity of rock paintings in Helan Mountain,Ningxia.In order to study the strength fracture pattern of rock art carrier material and spatial and temporal evolution of AE,uniaxial compression experiments are conducted to obtain the feature of AE,and a model is established for describing characteristics of the rock damage based on the cumulative ringing count.The results show that the rock failure is“conical”,and its damage development mainly experiences three evolutionary processes of primary crack closure,secondary crack development,and crack penetration failure.The mechanical and physical significance of the damage evolution model is clear.Acoustic emission characteristics are closely related to deformation characteristics,which can characterize the internal damage process of the rock,and can be used to determine the internal(micro)crack state of the rock sample.So it provides a solution for the crack propagation of rock cultural relic.