Rock Mechanical Parameter Inversion Based On DSCM-FEM

Rock mechanics parameters were the basic data of rock mechanics theoretical analysis and numerical calculation of water conservancy and hydropower engineering,transportation engineering and mining engineering.It was difficult to select mechanical parameters in rock engineering analysis because of the obvious heterogeneity of rock materials.Aiming at the inversion of mechanical parameters of heterogeneous rock materials,based on the rock deformation field data measured by the Digital Speckle Correlation Method,a rock mechanics parameter inversion method combining the Digital Speckle Correlation Method with the Finite Element Method was constructed.Through the three point bending experiment of granite and the uniaxial compression experiment of red sandstone,the inversion of rock boundary conditions,elastic parameters and damage parameters was carried out,which provides reference for the selection of mechanical parameters in rock engineering design.In terms of boundary condition inversion,the uniaxial compression experiment of red sandstone was carried out.The Digital Speckle Correlation Method and the Finite Element Method were used to analyze the displacement field of the specimen in the loading process.The element stiffness matrix and the parameter inversion equations were derived,and the boundary conditions of the upper and lower ends of the specimen under the unknown and known elastic parameters were calculated.In terms of elastic parameter inversion,a mechanical parameter inversion process combining the Digital Speckle Correlation Method and the Finite Element Model Updating was constructed.A three-point bending experiment of granite was carried out,the strain field during the loading process of the specimen was analyzed.The finite element numerical model corresponding to the experiment and the stress field of the model was extracted.The elastic parameter inversion objective function was constructed.Finally,the elastic parameter closest to the experiment was calculated.In terms of damage parameter inversion,based on the inversion process constructed above,the Digital Speckle Correlation Method was used to calculate the strain field of the specimen loading process.The experimental numerical calculation model was established,the rock damage equation was derived,and the damage parameter inversion was constructed.By performing the objective function,the damage parameters of the rock are optimized and obtained.