Numerical Simulation Study On Three-point Bending Dynamic Failure Process Of Rock

In the actual engineering study, the mechanical properties of the rock mass depends on many methods such as laboratory tests, outdoor tests, analytical methods and numerical simulation. As a relatively new research method, numerical method is a complement for the experimental method and theoretical analysis method. With the calculation software development and the continuous development of the computing power, the value is now the majority of engineering practice adopted to solve the problem of difficult to explain using the test methods and theoretical approaches. Compared with the experimental and theoretical research methods, numerical experiments show the great advantage of a more intuitive and able to handle more complex engineering problems.Rock materials are different from the isotropic material such as steel, and also different from the soil of this granular material. The rock is a brittle or quasi-brittle materials. There are some differences between the dynamic characteristics of the rock material and static characteristics. However, in engineering practice, it is difficult to see the pristine force of circumstances. Therefore, the study on the dynamic characteristics of rock materials is particularly important.This article is about dynamic characteristics of the rock material which is based on a three-point bending beam test and the results of previous studies. With the help of a real rock failure process analysis software dynamic version (RFPA2D-dynamic), this paper do the study on the three point bending test of rock materials without pre-crack firstly. In this study, peak loads and loading rates have been taken into considered, and get the result that the split time and the damage scale of the specimen increased with the growth of the peak loads and loading rates. After that, combined with previous experimental, a study on three-point bending beam with pre-crack under different peak loads and loading rates has been done, and found that when the angle of the pre-crack and loading direction increases, the time of the specimen start spreading gets earlier, and also found that the increase of peak load and load rate will cause destruction starting time advanced and the destruction scale increased. At last, this paper studied the critical position corresponding the mixed failure modes, and considered the factor of homogeneity and peak loads, got some regularities, such as when the peak load was fixed, the values of the critical positions were increased with the increase of the homogeneity; when the homogeneity was fixed, the values of the critical positions were reduced with the increase of the peak loads.