中文摘要：

为探究直接拉伸作用下岩石力学特性和损伤演化特征,对3种岩石试样进行单轴直接拉伸声发射测试,分析岩石的直接拉伸力学性能及声发射活动规律。结果表明,岩石试样的拉伸应力-应变曲线在试验加载初期表现为线性关系,随着载荷增加,应力-应变曲线缓慢弯曲;拉伸破坏前试样没有明显的屈服阶段,拉伸宏观破坏瞬间产生,没有峰后曲线;随着拉伸应力的增加,岩石内部低强度晶体或微裂隙发生破坏或扩展,使试样抵抗拉伸变形能力减弱,表现为试样拉伸弹模随拉应力增加而下降。拉伸过程中的AE活动对应着岩石内部微损伤的产生和发展,拉伸过程的初期和中期AE事件极少,在试样拉断破坏之前,声发射事件急剧增多,强度和能量急剧增大,远远大于前期AE信号的幅度。AE事件的位置分布与试样的宏观破坏面有较好的对应关系,表明实时分析AE或微震活动,可以分析岩石内部的损伤状态和破坏位置。

英文摘要：

To study the mechanical characteristics and the damage evolution process of rock under direct tensile loads,three different kinds of rock specimens had been carried out acoustic emission（ AE） testing under uniaxial direct tension. The direct tensile mechanical properties of rocks and the AE activities rules were analyzed. The results show that rock specimen tensile stress-strain curve is linear at the beginning of the test loading. With the increase of load,stress and strain curve is bending slowly. Samples have no significant yield stage before the tension failure,tensile macroscopic damage instantly occurs with no curve after peak. Along with the increase of tensile stress rock internal low intensity crystal and micro cracks occur damage or extensions,which makes the ability to resist tensile deformation turn weak. Specimen tensile elastic modulus decreases as the increase of tensile stress. The formation and development of micro damage in rock is corresponding to the AE activity in the process of tension. There are very few AE events in the early and mid-stretching process. Before specimen tension failure,AE events,strength and energy increase rapidly and the AE signal is greater than that of the early stage. The position distribution of AE events has a good corresponding relationship with the macroscopic failure surface of the sample. It is indicated that analysis the AE or seismic activity in a real-time can analyse the rock inside damage state and failure location.