Three-dimensional Stress State Of Rock Fracture Crack Orientation And Expanding Characteristics

In many fields of rock mechanics and petroleum engineering and in-situ stress measurements, research drilling rock crevices and cracks Direction of crack propagation characteristics of rock drilling is a hot topic. Expansion of rock cracking and crack is a difficult problem has always been the concern of scholars, previous studies mostly limited to two-dimensional crack, and three-dimensional stress state of rock drilling under study crack crack orientation and crack propagation characteristics has been in the lack of a systematic study the initial stage. In this paper, the finite element method to solve this problem of cracks in the rock drilling crack orientation and crack propagation characteristics of three-dimensional stress state was studied system to ABAQUS finite element software simulation platform twelve cracking group azimuth, and in the appropriate orientation cracking crack propagation was simulated to obtain the corresponding conclusions, rock fracturing as a reference project.In this paper, we selected twelve three-dimensional stress state, taking into account characteristics of the rock elastoplastic finite element method to calculate the azimuth of each three-dimensional crack under the stress state, and calculated based on the theory of elasticity and cracking the azimuth Compared. The results showed that at twelve farming elastoplastic stress state of rock considering characteristics calculated using the finite element method of rock drilling crack fracture azimuth more realistic situation, the results are more accurate.In ABAQUS finite element software for the platform XFEM(Extended Finite Element) method, on the basis of the calculated crack azimuth angle of the two-dimensional plane strain state, three-dimensional stress state vertical wells, inclined three-dimensional stress state, respectively prefabricated crack crack under the extended simulation calculations and from the crack propagation path, the crack tip stress, through the cracks in terms of stress-strain curve of the unit, the crack propagation process of energy change calculation results are analyzed in detail to give a corresponding crack propagation characteristics.