RFPA（Realistic Failure Process Analysis）software training will be carried out in room 211 of SKLGP at 14:30 on next Monday(December 9), including theory and practical operation. Teachers and students interested in this training are welcome.

Realistic Failure Process Analysis (short for RFPA) software is a numerical test tool developed based on the RFPA method (realistic failure process analysis method) to simulate progressive failure of materials. On the basis of finite element theory and statistical damage theory, its calculation method considers the heterogeneity of material properties and distribution of defects in randomness, and combines the statistical distribution hypothesis of the material properties with the numerical calculation method (finite element method) to make damage processing to the unit which conforms to the given strength criterion, so as to make numerical simulation in the heterogeneity material failure. Because of its unique method of calculation and analysis, RFPA software can help solving many problems that cannot be resolved by most simulation software in geotechnical engineering.

The software purchased this time includes RFPA2D-Basic[basic version], RFPA3D-Basic[basic version], RFPA3D-Flow[seepage analysis version], RFPA3D-Centrifugal[centrifugal load version], RFPA3D-Engineering[project construction template version] series software, which can be used to make numerical simulation of load fracture of rock specimen, acoustic emission of rock rupture, the three dimensional crack propagation and interaction and the fracture of composite materials, and make application analysis of practical engineering such as damage to underground structure engineering and concrete structure. Multi-angle rotation and different azimuth shear models can be made too. The spatial and temporal distribution characteristics of initiation cracks, stress field, displacement field and acoustic emission field can be observed.

State Key Laboratory of Geohazard Prevention and Geoenvironment Protection(SKLGP), CDUT

December 7, 2019

**[Attachment: software introduction]**

**Basic Version—RFPA2D-Basic**

2D Realistic Failure Process Analysis Software[basic version]— RFPA^{2D}-Basic is the most basic version of RFPA^{2D} software, which integrates the basic functions of RFPA^{2D} software, including pre-processing modeling module, finite element calculation, and post-processing analysis independent module. It can meet the requirements of basic experimental teaching of rock mechanics and can be used to analyze the deformation and failure of brittle materials such as rock and concrete under load, to detect the acoustic emission mode, and conduct simple engineering application analysis, such as stress field, displacement field monitoring and acoustic emission (micro-seismic) monitoring in underground engineering excavation and support.

[Typical examples]

Uniaxial compression failure and acoustic emission model of rock samples (RFPA^{2D}-Basic simulation)

Uniaxial stretch, compressive failure and load step curve of rock samples (RFPA^{2D}-Basic simulation)

Distribution of ground stress field caused by excavation of underground engineering(RFPA^{2D}-Basic simulation)

Simulation results of loading failure of specimen with preset double cracks(RFPA^{2D}-Basic simulation)

Shear simulation results of contact surface(RFPA^{2D}-Basic simulation)

Numerical simulation results of rock particle fracture(RFPA^{2D}-Basic simulation)

Numerical simulation results of Brazilian experiment(RFPA^{2D}-Basic simulation)

Numerical simulation of rock breaking process by cutters(RFPA^{2D}-Basic simulation)

**Basic version—RFPA3D-Basic**

3D Real Failure Process Analysis Software[basic version]—the research on 3D failure process of rock has been facing many difficulties due to complex mathematical theory and the limitation of the laboratory experiment and field observation test conditions. The RFPA^{3D} series software is designed to overcome the above difficulties. With its the unique characteristics of rock failure process analysis, the software can be used to make numerical simulation of load fracture of rock specimen, acoustic emission of rock rupture, the three dimensional crack propagation and interaction and the fracture of composite materials, and make application analysis of practical engineering such as damage to underground structure engineering and concrete structure damage.

[Typical examples]

Elastic modulus and axial displacement of rock samples failure under axial compression (RFPA^{3D}-Basic simulation)

Five-point bending load failure process of brittle material sheet (RFPA^{3D}-Basic simulation)

Three-point load failure of concrete beams (RFPA^{3D}-Basic simulation)

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**Centrifugal Loading Version-RFPA3D-Centrifugal**

3D Real Fracture Process Analysis Software[centrifugal loading version]—FPA3D-Centrifugal is a new version based on RFPA3D-Basic, which introduces the basic principles of centrifugal loading test into the real fracture process analysis[RFPA] method. RFPA3D-Centrifugal is based on the knowledge of the meso-level structure of rocks. We assume that the meso-mechanical properties of rocks are statistical, discretizing the rocks into meso-scale primitives of an appropriate scale. Considering its heterogeneity characteristics and with the given Weibull statistical distribution Function, we assign the mechanical properties of these elements. These meso-level primitives can be used to calculate the displacements and stresses under load conditions with the finite element method as a stress analysis tool. On the basis of that, by the analysis of primitives failures, we investigate whether the primitives are destroyed and obtain a new state of the material properties of the primitives. The RFPA3D-Centrifugal increases the weight of the meso-primitives gradually in a linear way and a certain step length. Each time the weight increases, the finite element calculation program makes iteration calculation, strikes a balance between the external and internal forces and makes analysis of damage at the same time, until the macroscopic failure of slope instability, the sliding failure surface are obtained by the numerical model, so that we can get the calculation steps of maximum damage unit number as the critical point of the slope instability to make corresponding safety coefficient calculation.

[Typical examples]

3D slope stability analysis of ordinary slopes (RFPA^{3D}-Centrifugal)

3D slope stability analysis of on irregular slopes (RFPA^{3D}-Centrifugal)

Multi-step 3D slope stability analysis (RFPA^{3D}-Centrifugal)

**Engineering Modeling Version—RFPA3D-Engineering**

3D Real Fracture Process Analysis Software[engineering modeling version] —RFPA3D-Engineering is mainly for practical geotechnical engineering application analysis, which can perform stress analysis, displacement monitoring and acoustic emission(micro-seismic) monitoring of engineering entities. For the actual engineering model, RFPA^{3D}-Engineering itself can be used for modeling and calculation analysis, or large-scale general commercial software such as MSC.PATRAN, ANSYS can be used for modeling, and then imported into RFPA^{3D}-Engineering for calculation and analysis. Finally, the visual results and specific quantitative analyze data are obtained.

[Typical examples]

Damage of arch dams under seismic waves (RFPA^{3D}-Engineering simulation)

Maximum principal stress distribution obtained from RFPA^{3D}-Engineering numerical simulation

The process of crack formation on the sphere surface (the process from crack generation to saturation) (r3-r2 = 30mm)

Spherical surface crack formation process (simulation results of different material layer thicknesses) (RFPA^{3D}-Engineering simulation)

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**Seepage Analysis Version—RFPA3D-Flow**

3D Real Fracture Process Analysis Software[seepage analysis version] —RFPA-Flow can be used to establish a physical model describing the seepage-stress-damage coupling of heterogeneous rock masses, and study the changes in stress state of rock masses and the impact of permeability evolutionary laws in damage and failure on the seepage process including the analysis of the entire process of stress-strain-permeability coefficient, and the law of permeability change during the process of crack initiation and propagation; the effect of seepage process on the stress distribution and damage evolution of rocks under water pressure, including the effect of pore water pressure on rock failure modes; the effect of heterogeneity on the seepage-stress-damage coupling mechanism of rocks; this version can be used to make simulation research on basic seepage characteristics of rocks (mass), numerical calculation and analysis of fluid-solid coupling problems of rocks (mass) in hydraulic engineering. For example, the calculation and analysis of seepage fields of various dam bodies, spore pressure fields and micro-seismic space-time distribution can be made, and we can also make a prediction and an analysis of sudden geological disasters such as water inrush in confined water and coal seam mining.

[Typical examples]

Numerical model failure mode (water pressure distribution)