岩石多功能剪切试验测试系统研制

详细介绍了所研制的岩石多功能剪切试验测试系统的主要功能、技术指标和仪器组成，并开展了一系列相关力学试验。该试验测试系统主要包括试验装置、测量系统和控制系统3部分，最大法向拉伸应力为40 MPa，最大法向压缩应力为120 MPa，最大水平剪切应力为120 MPa，试样尺寸为50 mm?50 mm?50 mm；可开展多种力学试验，包括直接拉伸试验、直接剪切试验、拉伸-剪切试验和压缩–剪切试验。利用该试验测试系统对花岗岩进行试验研究，研究结果表明：直接拉伸试验中，试样发生脆性破坏，声发射信号瞬间达到峰值，破坏断面表现出拉伸破坏特征；直接剪切试验中，试样发生多次破坏，破坏瞬间声发射信号均发生突增，破坏断面表现出剪切破坏特征；拉伸-剪切试验中，试样在拉应力作用下剪切强度显著降低，声发射信号在破坏阶段表现强烈，破坏断面既有拉伸破坏特征也有一定的剪切破坏特征。上述力学试验结果，表明了所研制的岩石多功能剪切试验测试系统能够开展多种力学试验，为进一步研究岩石的剪切力学特性提供新的测试手段。

Development of a multi-functional shear test system for rock

This study introduces the main function, technical index and instrument composition of a developed rock multi-functional shear test system in detail. A series of mechanical experiments is carried out by using the testing system. This system mainly consists of three parts: testing device, measurement system and control system. The maximum normal tensile stress is 40 MPa, and both the maximum normal compressive stress and horizontal shearing stress are 120 MPa. The specimen size is 50 mm?50 mm?50 mm. Multiple mechanical experiments are conducted on granite, including direct tension test, direct shear test, tension-shear test and compression-shear test. The results show that brittle fracture of the specimen occurrs in the direct tensile tests. The acoustic emission (AE) signal instantly reaches the peak and the fracture surface exhibits the characteristics of tensile fracture. In the direct shear test, the specimen is destroyed many times. The AE signal suddenly increases at the moment of destruction, and the fracture surface shows the characteristics of shear fracture. In the tension-shear test, the shear strength of the specimen decreases significantly under the tensile stress. The AE signal is obvious at the failure stage, and the fracture surface exhibited both tensile and shear fracture characteristics. The results of the above mechanical experiments indicate that the developed multi-functional shear test system can successfully carry out a variety of mechanical experiments and provide a new testing method to further study shearing properties of rocks.